Kathryn Lasky (published March 1, 1999)
Jean Martin
Charles wrote his last book at the age of 58 years old and wrote his first book at the age of 24 years old.
26
he was 56 wrote his first book
Mary Shelley was 20 years old when she wrote her first book, "Frankenstein".
28
Isaac Asimov was 21 years old when he wrote his first book, "Marooned off Vesta."
John Boyne was 29 years old when he wrote his first book, "The Thief of Time," which was published in 2000.
enid blyton was 14 when she wrote her first book "childrens whisper"
she was 90 when she wrote her lat book "The First Four Years"
She was 9
Looking at some of his websites and info it s unknown when he wrote his first book he wrote story's at the age of 12 and at 19 wrote a book (around 19).