The Telegraph understands she suffered from the childhood cancerous condition, which returned later in life.
Lesley-Ann Jones, author of Love, Freddie: Freddie Mercury’s Secret Life and Love, which revealed the existence of the singer’s child, told the Telegraph: “I can say now that I knew all along, while we were writing the book, that she may not live to see it published. The fact that she did was a miracle.
“Her childhood chordoma, a rare cancer that affected the base of her spine, had long been in remission. It then reared. She always knew that it would.
“The illness was the deciding factor in her decision to contact me, to tell me Freddie’s story.
“She did not do it for money. Nor did she pay me. Nor would I have accepted payment from her. The mission was always to give her father back his truth … as it were, warts and all.”
In August, B revealed how she did not want to share her father “with the world”. It was previously thought he had no children.
Last summer, she said: “After his death, I had to learn to live with the attacks against him, the misrepresentations of him, and with the feeling that my dad now belonged to everyone.
“I cried and mourned my dad, while fans all around the world mourned Freddie. When you are 15, it’s not easy. I had to become an adult without him, and live all the structuring moments and events without his support.”
The book is based on 17 handwritten diaries that Mercury gave B three weeks before he died on November 24, 1991, because of health complications related to Aids.
Queen fans were surprised at learning that he had a daughter, who was conceived accidentally during a fling with the wife of a close friend in 1976, a year after Bohemian Rhapsody was a hit.
Mary Austin, Mercury’s former lover and friend, who inherited around half of the singer’s estimated £9m ($21m) estate, is alleged to have said she was unaware of B’s existence. B said she was “devastated” by the alleged response.
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