“If it was your own child and she had a career in front of her, and she was being successful in it, what would you think?

“Would you let her do it or would you say, that’s enough, let us have her back?”

Victor Zavaroni, father of child singing star Lena, relates the dilemma he faced in the 1970s.

His wee girl had hit the big time on the decade’s equivalent of Britain’s Got Talent, and she was catapulted to the top of the entertainment world.

But in the days before talent show age restrictions and contestant welfare policies, showbusiness took a toll on her health, leaving her family wondering if handing her her dream was a mistake.

It was a fairytale without a happy ending.

A new BBC Scotland documentary charts the child star’s rise to fame.

Lena was just a little girl when her potential was spotted by a music producer on holiday in her home town of Rothesay, on the Isle of Bute.

Not long after he heard her sing, a showbiz agent flew north with a management contract.

Victor Zavaroni recalls that Philip Solomon was in no mood for any negotiation.

“I asked him ‘Do you mind if I get a lawyer?’.

“‘No, No, No, he said. This doesn’t need a lawyer.”

Solomon stormed off with his offer, leaving Victor stunned.

“I went to my cousin and he said, are you sure you are doing the right thing there Victor, this guy might help Lena get on.

“And that’s how it happened,” he said. “I signed it.”

Contract sealed, all the family assembled to wave Lena off when she headed down to London, a youngster from a tiny Scottish island off to seek fame and fortune.

First up was an appearance on the biggest TV talent show of the time – Opportunity Knocks .

She belted out a fierce rendition of “Ma, he’s making eyes at me,” winning the show and the hearts of the nation with her white knee-length socks, bows in her hair, and a pinafore dress.

She was nine years old. It seemed there was no stopping her.

Soon she was off on a tour of America, meeting Frank Sinatra, appearing on the same bill as Liza Minelli and being interviewed on the Tonight Show with Johnny Carson.

There were dates in Japan and throughout Europe. All this meant Lena was away from home, and her mum and dad, for a long time.

She was living in London with her managers Philip and Dorothy Solomon, or out on the road with them.

Dad Victor and the family were so proud of all she was achieving, but he remembers when that parental pride turned to worry.

“She came home when she was coming up to Scotland for a couple of weeks and I noticed she was very, very, thin.”

Victor felt she should not have been as thin as she was.

“I took her to the doctor’s and he says to me ‘Your daughter’s got anorexia nervosa’. I never heard the word anorexia for sure. It wasn’t a known thing. It wasn’t a known illness,” he said.

Victor said that after doctor’s advice that Lena might do better living with the family, they moved south.

But the comfort and routine of being back with her Mum and Dad and sister, was no match for the illness.

Victor remembers “She was losing more weight and I was trying to make her eat night after night after night, but it was seemingly getting worse.

“I went everywhere for help, specialists, psychiatrists, hypnotherapists, psychoanalysts, it was all trial and error and it just wasn’t working – even with the doctors she was seeing.”

Eventually Lena became so ill she had to stop performing, but a few years later she returned to Rothesay to take part in a special Songs of Praise.

In an interview for the programme, still battling anorexia and depression, she spoke of keeping faith that better days would come.

“There is always hope at any time of life, and I think you’ve just got to think that, whether you feel it or not,” she said.

Just six years later, in 1999, it was that hope of having better health and returning to her singing career, which led Lena to undergo brain surgery she hoped would cure her.

Dad Victor, after visiting her in hospital, thought the operation may have worked.

“I honestly think when I went to see her, she was starting to eat , I honestly do, but I’ll never know,” he said.

Lena died of pneumonia after the operation. She was 35.

Looking back on recordings of Lena singing for the documentary, Victor watches and listens closely to a TV performance by his 18-year-old daughter.

She is singing, standing at the microphone, elegant in a long dress, sequins twinkling under the studio lights.

She is pitch perfect. The power of her voice in contrast to her own vulnerability. Or perhaps it was because of her vulnerability, she seemed to feel every word.

“She was in a world of her own singing, there’s a lot of feeling in that,” said Victor.

“Well done, hen.”

Lena Zavaroni: The Forgotten Child Star

Sunday 6 October, BBC Scotland, 21:00

If you, or someone you know, have been affected by eating disorders, you can find help and advice at the BBC Action Line.