Billie Josiah never saw her cousin Leona triumph, never saw Leona become the singing star she had always known she’d become.

Billie lost her battle with leukaemia before her cousin won X-Factor and became the megastar she is today. But Leona Lewis will never forget the bright and gifted youngster whose memory has been such an inspiration to her.

This week Leona waived her £100,000 fee to front the Teenage Cancer Trust’s summer campaign against skin cancer.

And now Billie’s mum Becki has spoken for the first time about losing her only daughter, of her closeness to Leona and the heartbreak her death two years ago brought the singer.

Mum-of-four Becki said: “They were so very alike, both very gentle, caring and composed.

“They had little things that are so similar. There is this little wave that Leona does and when I see her do it, it reminds me straight away of Billie. It breaks my heart sometimes.

“Leona would come and visit with all of her other cousins and they all got along really well. We have such a strong family and that always meant the world to Billie.”

Billie’s father Aubrey, 38, added: “Billie and Leona had this plan to go to America together - I used to let her watch Jerry Springer and then ask, ‘Do you still want to go?’ They would text and call each other a lot. Leona and all of Billie’s cousins showered her with a lifetime of love in the last few weeks of her life.”

Billie had led a healthy, active lifestyle, so when she was first diagnosed in 2004 with leukaemia, her family were in shock.

“Billie had been ill for a few weeks. We took her to see the GP and could never have expected the news”, recalls Becki. “But Billie took it really well and she trusted us when we told her what she may have to go through, she never cried or made any fuss.

“She made it easy for us as parents and as a family to deal with the whole process. She was so mature about everything.”

The walls of the family home in Walthamstow, East London, are adorned with dozens of picture of Billie and there is a lovingly-tended memorial garden dedicated to her.

When her health deteriorated, Billie was forced to leave the school she loved and give up the sports and pastimes she enjoyed.

After 18 months of stressful treatment, the family had hoped she was making progress but then came the devastating news that she had suffered a relapse.

It was then that Billie herself made the decision to stop with her chemotherapy and to leave hospital.

Becki added: “She wanted her last few weeks to be as normal as possible. She started crying and then said, ‘I’m so happy - I’m going home.’

“She said thank you to all the doctors and to everyone who had helped look after her. One of the doctors told her that it was against the rules for him to have favourites - but she had made a real difference to the ward.

“Billie wanted to make the most of her time left. We were told she only had two weeks, but she was with us for six.

“She had wanted to be a model, a lawyer and a dancer - she loved school and found it really difficult to leave. She loved netball, but there came a time when she was just too weak and had to stop.”

When Billie died on April 27, 2006, Leona was still an unknown singer, with dreams of pop success. At Billie’s funeral, she sang an emotional version of Over The Rainbow… which she would later perform on the X-Factor.

Leona said recently: “Billie was only 14, but I try and draw on the positives. She had such a wonderful impact on so many people. She was such a ray of light.

“When I sang Over The Rainbow on X-Factor, it was for Billie, because I sang it at her funeral and that was a way of remembering her.”

Becki says: “We always knew that singing was what Leona was destined to do. She has always had what it takes to make it big.

“Billie would be so proud what Leona has achieved today. It would have been so exciting for her, because she loved all the celebrity stuff.” The fact that Leona has turned down a £100,000 fee to be part of the summer campaign for Teenage Cancer Trust comes as no surprise to Becki.

“I am really pleased with what Leona has done for charity,” she said. “I am very limited to what I can do but someone like Leona, with her profile, can make a real difference.”

Billie had a particularly aggressive form of leukaemia and her chances of survival were further reduced because of Aubrey’s Guyanan heritage.

When children such as Billie contract cancerous diseases such as leukaemia, they face a double difficulty because mixed-race stem cell donors, as well as donors from many ethnic minorities, are almost always unavailable from any donor bank. Now, Becki works with charities CLIC Sargent and the African Caribbean Leukaemia Trust to publicise the issue further.

“Children with leukaemia need a lot of blood transfusions. If Billie had not had the transfusions that were available to her she would never have been able to come home,” says Becki.

“I do encourage people to give blood as and when they can, especially young people. All of the children suffer so much and all we can do is help them in any way we can.”

Thanks to Becki’s dedication to her daughter and Leona’s tireless charity work, the memory of Billie will live on.

“Leona and everybody else loved Billie, because she was always smiling,” says Becki. “I miss her every day and that will never change. People think they know what a broken heart feels like but until you lose a child you will never know. One of the things Billie asked when she knew she was going to die was, ‘Will people remember me?’ and I just want to help keep her memory alive.

“I am sure Billie is looking down and is incredibly proud of everything Leona has done and everything that she stands for.”