Over the past few months Lorna Luft has watched a drama unfold just yards from the grounds of her Los Angeles home. It's a drama that most of us have only glimpsed through the pages of tabloid newspapers and magazines.

It is the drama of Britney Spears, whose lifestyle appears to have become increasingly bizarre if the news reports and headlines highlighting her every cough and spit are to be believed.

The young singer - or troubled star' as she's usually referred to - lives in Lorna Luft's LA neighbourhood. Lorna has watched in despair as paparazzi, camera crews and occasionally the emergency services gather in packs outside her home and helicopters circle the sky. Lorna's own children have been grilled for information by the press stalking Britney's home.

"It all seems very sad," I remark, thinking of recent press photographs of Britney being carried from her home on a stretcher, looking like a frightened animal as she stared into one of the many cameras that follow her everywhere and must make her life a misery.

"Yes it's sad, but there comes a time when the sympathy has to stop," says Lorna, firmly. "When someone is a grown adult and there is help out there for them, they have to take responsibility for their own actions. Especially when they have children."

Lorna, 56, knows more than most about the demons facing young stars, and the tragic legacy those demons can leave. She is the daughter of Judy Garland, who shot to fame as a child star and died a broken drug addict.

Lorna is the daughter of Garland and her manager and third husband, Sidney Luft. She is the half-sister of Liza Minnelli.

She explores her relationship with her mother in her stage show, Songs My Mother Taught Me, which comes to Bradford next month.

At the age of 12 Lorna was looking after her increasingly fragile mother, giving her medication and trying to prevent her from killing herself. It's a chapter of Lorna's life documented in her best-selling memoir, Me and My Shadows, made into a multi Emmy award-winning TV drama starring Judy Davis as a chillingly accurate Garland.

"I took on the role of mother," says Lorna. "My mother lost sense of reality, the legend of Judy Garland took over her life and overwhelmed her, that can happen when fame takes a grip."

Although she made more than two dozen films as a child, it was 1939 movie The Wizard of Oz that shot Garland to fame at the age of 16. She went on to earn international acclaim in movies and concerts but behind the professional triumphs she battled insecurities; as a young star she was told she was fat and unattractive and was fed drugs to control her weight and boost energy, leading to a life-long struggle with addiction. She attempted suicide several times and died of a drug overdose aged 47.

Her daughters also battled with high-profile addictions, so Lorna knows what it's like to be a troubled star.' "I saw at first-hand what this business can do when you're too young to handle it. My mother didn't have a chance," she says. "She was exploited and she had no help. Back then they didn't see what she had as an addiction', they called it a mystery illness.' And there was a stigma with getting help.

"These days there's more help out there than ever. It's up to those who need it to take it. I've been sober for 24 years; it can be done but you have to want it."

Because of her childhood experiences, Lorna feels strongly about cultivating a stable environment for her own children, Jesse and Vanessa, from her first marriage to musician Jake Hooker.

"For me, going into showbusiness was like joining the family business," says Lorna. "If you come from a family of lawyers you become a lawyer, it was like that. But thankfully my children haven't gone into this business. My son's a stockbroker and my daughter is studying.

"When I look at kids in this industry who get in trouble I think Where are the parents?' Having a supportive family to guide you is one of the most important things in life. My advice is to hang on to your family.

"Look at the Osmonds; I knew them as kids and they were and have remained grounded because they had good parenting. They see the world beyond their own bubble of fame.

"I met the Spice Girls recently, they're delightful. The Beckhams live near me in LA and they're a very strong family unit, great role models. I think that's partly because they came from strong supportive families."

But even with a loving, supportive family, surely young stars can still go off the rails.

"Celebrity is like a drug and it's easy to get carried away. It can make you fragile - I hope what happened to Heath Ledger this week is a wake-up call for kids coming into this business," says Lorna.

"He was a great talent, but we also have the kids who are famous for what, exactly? If you sell your soul to the Devil and invite the press into corners of your life, if you choose to be photographed falling out of cars with no knickers on, you take the consequences. There's a man who's on American TV every night, he's one of the most famous people in this country, but I know nothing about his private life. He's called David Letterman. You can be a big star and still have privacy, it depends how you play the game."

Not surprisingly, in the light of what her mother went through, Lorna despairs of fame coming too young. She speaks from experience; she made her TV debut aged 11, joining her mother on the Judy Garland Show. At 16, already a seasoned performer, she shared the bill with her on Broadway. By 19 she was starring in the Broadway hit, Promises, Promises, and went on to carve a 40-year career on stage, film and TV.

"I've seen more child stars than you can imagine and I can tell you that it's what their mothers want," says Lorna. "I've seen six-year-old kids working so hard on TV shows and their parents say: It's what they want.' How do they know it's what they want? Do they have a choice? Do they really want to sacrifice their childhood for a heavy work schedule and the pressures of fame? I don't think so.

"When children have all that so young, without the freedom to enjoy being a child, is it surprising they eventually go a little crazy? I've seen this movie - I know how it ends."

Songs My Mother Taught Me is billed as a celebration of "the legend, music and memories of Judy Garland," with Lorna performing some of her mother's best-known songs.

"It's very personal to me," says Lorna. "Judy Garland was a legend to everyone else but to me she was my mother. This is a show for families and especially mothers and daughters. I believe that you don't get to know your parents until you're in your 40s. That's when you see their real identities.

"People come backstage and tell their kids, That lady's mom was Dorothy.' I want to show that she was much more than Dorothy." It was Lorna's close friend, Barry Manilow, who urged her to pay tribute to her mother.

"For a long time the legacy was just too overwhelming but eventually I became more comfortable with it. Endless books have been written about my mother, but none of the authors came to our home, they didn't know her," she says. "The context of the show is music, but it's also about memories. I take the audience on a journey of my mother's life, but how it relates to me. We laugh, we cry, we sing, we joke and we celebrate the joy that was and still is my mom and her music.

"I feel her with me all the time. This is my love letter to her, my way of saying thank you."

  • Lorna Luft's Songs My Mother Taught Me is at St George's Hall on Wednesday, February 13, at 7.30pm. For tickets ring (01274) 432000.