Lily Allen says it would be hypocritical to stop her daughter's taking drugs when they're older.
The 'Hard Out Here' singer - who has admitted to a wild past including cocaine - has insisted she isn't in a position to tell Ethel, two, and Marnie, one, about the dangers.
Lily - now reformed - told BBC Radio 4's Desert Island Discs: "I can't really do anything but be there for them.
"People are going to do what they want to do, quite rightly. They'll say, 'You're a hypocrite. You went an experiment and you said it was a right laugh so what do you mean I can't?'
"But I've seen so much of it growing up and I've seen people really lose the plot and die."
Meanwhile, Lily has praised her husband Sam Cooper for helping her overcome her personal problems by showing up "at the right moment".
She added: "One of the many amazing things about my husband is that he came along just at the right moment when things could have really gone south. I was really manic.
"I was on the road, being chased by people. My life was splashed all over the papers, people in my group of friends were selling stories about me.
"Feeling like you can't trust anyone in your circle brings on horrible spells of paranoia. My way of coping with it was by not eating very much as a control thing and to get out of it and as wasted as I possibly could."

Dolly Parton was "so excited" when Adele asked to write with her.
The '9 to 5' singer has heaped praise on the 'Skyfall' hitmaker and fueled speculation the pair could collaborate on a track after admitting she was "honoured" to have her as a fan.
She told The Sun on Sunday newspaper: "I was so excited a year or so ago because I was hearing she was coming to Nashville and wanted to write with me.
"I was honoured to find out she's a fan because I think she's spectacular."
The music icon also had kind words for fellow star Taylor Swift, who she insisted has "handled herself" well.
She said: "I know her and her family. She's a great girl and a big talent. I admire her a lot for how she's handled herself."
Meanwhile, Dolly praised Taylor's ex-boyfriend Harry Styles and the rest of One Direction, although she didn't know the boyband were "all British".
She admitted: "They're fantastic but I didn't realise they were all British. I've heard all the music and they're great. They're good-looking kids."

Lorde worries she may not have a career by the time she reaches 25.
The 17-year-old singer has been praised for capturing the spirit of today's youth in her music, including hit song 'Royals', but she admits she isn't sure people will care about her music when she grows up.
She explained: "Since I started making music, a lot was made of how old I was and it made me think about, what happens when I'm 25? Will people still like what I'm doing? Will it still be important if I'm not this hyper-youthful being?
"It's stupid, I know I'm being silly, but I can't help it. It's just one of those things. I'll get over it."
The 'Team' hitmaker also reveals she is conscious of the pressures to look perfect in the music industry and how it might affect her fans.
Lorde said: "I am a young person and I know how it feels to have those pressures of not looking a certain way. A lot of people have misconceptions about this industry and how you're supposed to look. I don't think I should have to look perfect all the time.
"I definitely think about the imprint I'm leaving on people my age - particularly girls. I'm sensitive to how women are portrayed because sometimes it kind of sucks."
The New Zealander thinks she has "thicker skin" than most and isn't easily offended by detractors claiming she looks older than her years.
She added in an interview with Bliss magazine: "I always get these weird people being like, 'Oh, she's growing up too fast, she looks 30.'
"I've grown a way thicker skin in terms of my own appearance. People don't hire me for how I look, but for what I do and the talents I have, which is cool."

Keira Knightley finds romantic comedies "tricky".
The 29-year-old actress tends to avoid signing up to star in lighter films, but couldn't resist starring alongside Adam Levine and Mark Ruffalo in the quirky new musical rom-com 'Begin Again'.
She said: "After 'Anna Karenina', I realised that I'd done five years of work where I'd died or something horrific had happened to me in absolutely everything. I wanted something more positive and with hope in it.
"Romantic comedy isn't a genre I usually go to - it's one that I find quite tricky, but I thought this was strange enough with enough of a sort of acerbic quality to it."
Knightley is used to playing dramatic roles in movies such as 'Anna Karenina', but felt it was "important" to play something lighter so fans don't get sick of her.
She explained to Britain's HELLO! magazine: "It's what keeps it interesting and means that you don't stagnate. 'Begin Again' sent me out of every sort of comfort zone that I thought I had - the way of working, the type of film, the sort of character. It was totally different. I thought that was a good thing to do."

Lana Del Rey wants to be a biker.
The 'Video Games' singer has always wanted to be a leather-clad, cross-country driving motorbiker and hopes to fulfil her dream when her music career quietens down.
Discussing the casting of bikers in her video for 'Ride', she explained: "The reason why bikers and biker culture is so important to me is that we have the same principle in mind, freedom and staying free. For them that means being on two wheels on the road, which is why that's a recurring motif for me.
"I'm not able to be free like that right now, I still have a lot of work. What I aspire to be is probably on a bike on the road at some point."
Lana's lyrics always paint her as a Lolita-style ingénue embroiled with an older man, and she revealed she needs a more mature boyfriend to give her the intellectual stimulation.
The 27-year-old star told the 'Laura Leishman Project' show on French radio: "Knowing what I've wanted to do for so long, and being tamed in my own way for so long, the person I'm looking for is a more serene, intelligent and probably an older figure.
"I was aware that people would take [the older men] literally as an archetypal already been done, played on relationship. But for me I have more personal connection with the concept of a very giving, affectionate, older than me character."

Beyonce and Jay Z will "lead separate lives" on tour.
The couple - whose marriage has been the subject of speculation it is in crisis - kicked off their joint 'On the Run' concert series this week but they are said to be only seeing one another on stage, as they travel separately and stay in different hotel rooms.
A source said: "They might be sharing a stage, but while on tour they'll live practically separate lives.
"Tensions between them are worse than ever, meaning they will be travelling between venues independently, staying in different hotel suites and even having separate entourages..
"They'll also have individual dressing rooms, so the only times they'll be together will be while they're performing."
The couple - who have two-year-old daughter Blue Ivy together - have both been the subject of rumours of infidelity and the insider admits they are struggling to trust one another.
The source told Grazia magazine: "They've both been dreading the tour. Cancelling wasn't an option, so on the surface it's going to be business as usual, but they're both struggling with trust issues after the spate of cheating allegations.
Jay's given Beyonce unlimited access to his texts and emails to try and keep the peace, but a lot of their communication will be through assistants."
Despite the claims, the pair have seemed comfortable on stage with one another and even treated fans to previously-unseen footage from their wedding.

Mollie King longs for the "biggest family" and "the most incredible wedding".
The Saturdays star admits she has become obsessed with settling down after some of her bandmates have got married and had babies and hopes to one day start a family with music producer boyfriend Jordan Omley.
She said: "I want the biggest family and I want the most incredible wedding. It definitely gets you thinking about it."
Quizzed about marriage, she added: "Definitely one day, but not soon."
The 27-year-old starlet finds it difficult to maintain a long-term relationship - as she's based in the UK and her American boyfriend lives in Los Angeles - but believes her and Jordan's similar careers makes it easier for them to understand one another's busy schedule.
Mollie explained: "He's so kind and loving, he really looks after me. And because he's in the same industry, he gets it. He'll be talking about his day in the studio and I'll be talking about a performance."
As for communicating from different countries, the 'What About Us' hitmaker prefers video chats over Skype to phone calls.
She told Britain's OK! magazine: "With Skype I can put him there and walk around the kitchen and make my dinner."

Binky Felstead insists she needs to spend some alone time with Alex Mytton.
The 'Made In Chelsea' star has confessed she is now on speaking terms with her former boyfriend - who cheated on her on a number of occasions during the last series of the E4 reality series - and claims people need to understand that the situation is not as black-and-white as it seems.
She said: "What people watching didn't see before Alex cheated is that the two of us spent every day together and talked about our future. It's very difficult when you're in love to just turn that off and say no to the relationship.
"I need to have some alone time with Alex."
Despite appearing to fall out with close friends and co-stars, including Lucy Watson and Cheska Hull, during the cheating scandal, Binky claims she's had a lot of support and just needs time to decide how she will move forward.
She explained: "People may think I've been pushing my girlfriends away, but it isn't like that at all. It's very difficult to take their advice when your head is a mess and you're crying all the time, trying to make something work."
Binky added to Closer magazine: "They have all been amazing, I call them everyday. I've always valued my friendships."

Metallica headlined at Glastonbury tonight (27.06.14).
The heavy rock band - consisting of James Hetfield, Lars Ulrich, Kirk Hammet and Robert Trujillo - kicked off their energetic set on the Pyramid Stage at Worthy Farm in Somerset this evening with their classic hit 'Creeping Death', which had fans violently head-banging along.
The stage flashed with red and gold lights as the American quartet - who are the first metal act to headline the festival since 1970 - performed hits such as 'For Whom the Bell Tolls' and 'Wherever I May Roam'.
The group then got a little sentimental as they admitted they felt honoured to be representing heavy music.
Lead vocalist, James, 50, told the crowd: "Well Glastonbury, Metallica is grateful to be invited to such an event called Glastonbury.
"We're very proud to be here and to be representing, shall we say, the heavier side of music.
"Me and the boys would like to dedicate this new song to everyone here who's been waiting for someone like us and also to all the heavy metal British bands who have ever dreamed or are still dreaming of playing here."
He later dedicated their 2008 song 'Cyanide' to those whose soul has been moved by music.
The band then asked for the lights to be turned on so they could see "the Glastonbury family", before rounding off the show with their final song, 'Seek and Destroy'.

Lamar Odom reportedly told Khloé Kardashian he loves her on her 30th birthday yesterday (27.06.14).
The reality TV star filed for divorce from the 34-year-old basketball player in December, but he still reached out to her on her special day to declare his feelings for her.
A source told the HollywoodLife.com: "He made contact with Khloé on her birthday, but said it was real, real brief. He just wanted to tell her happy birthday and wish her well on this new decade in her life.
"He even told her he loves her and she said, 'Thank you,' but she didn't say I love you back. He was slightly hurt by that but he understood."
Despite Lamar's emotional message, Khloé didn't seem to let it put a dampener on her evening as she was spotted partying on a private yacht with her new boyfriend French Montana in New York City.
The 29-year-old rapper went on all out for the brunette beauty's milestone and spoiled her with over a $100,000 worth of gifts, including a $10,000 diamond gold grill, a $49,000 white Jeep and a $25,000 diamond ring.
Meanwhile, Khloé was left devastated last year when her four-year marriage broke down after rumours emerged that Lamar, 34, was addicted to cocaine and had cheated on her multiple times with different women.
The former couple's divorce is yet to be finalised.

Lana Del Rey played an emotional set at Glastonbury today (28.06.14).
The 'Blue Jeans' singer looked stunning in an orange, green and yellow tie dye dress on the Pyramid Stage as she performed some of her most heartbreaking songs - including 'Born To Die' and 'Summertime Sadness' - at the event at Worthy Farm in Somerset this afternoon.
The 28-year-old star appeared glum as she belted out the lyrics to 'Young and Beautiful' followed by tracks such as 'West Coast' from her new album 'Ultraviolence'.
At one point, she told the crowd: "I hope you guys are having the time of your lives."
However, some members of the crowd complained about her lack of conversation with the festival goers.
Although, fans seemed more than impressed when the brunette beauty - who was sporting her usual smudged black eyeliner - struck up a cigarette during her performance of 'Blue Jeans' as black and white videos flashed up on the screen behind her.
Lana then had an intimate moment on stage with her guitar player as she wrapped her arms around his waist as she looked out across the field at her adoring fans.
She finished off the show with 'Ride', 'Video Games' and 'National Anthem'.

Kim Kardashian and Kanye West want a "bigger" home in New York City.
The 37-year-old rapper already owns a bachelor pad in Soho, but him and his wife are reportedly on the hunt for a larger property in the big apple as they want their 12-month-old daughter North to have her own bedroom.
A source told PEOPLE.com: "They need a bigger space with private parking."
The couple, who got married last month in Florence, Italy, sparked rumours last week they were looking to buy a plush pad on the East Coast after Kim, 33, was spotted viewing a $21 million apartment on Lafayette Street with her half-sister Kendall, 18, and mother Kris Jenner, 58.
The brunette beauty also viewed a $17.25 million townhouse in Greenwich Village, which boasts six bedrooms, seven bathrooms, a secluded garden and private parking inside the building.
The 'Keeping Up with the Kardashians' star then took Kendall and Kris to see a $13 million penthouse, which comes with a stunning terrace and private pool.
Kim, Kanye and North are currently staying at Kris' home in Los Angeles while they wait for the renovations on their new Bel Air mansion to be completed.
The family were hoping to move into the property at the end of last year but, after a few electrical glitches, their moving date has been pushed back until later this year.