US pop sensation Miley Cyrus has finished writing a book of her life at the age of 15. The star of hit TV show Hannah Montana was reportedly paid a seven-figure sum to tell her "inspiring story".  The daughter of country singer Billy Ray Cyrus has also said she wants to return to the show for a fourth series. "Hopefully I'm going to go into season four, but we're not sure so right now we're just getting through season three," she told BBC News. Cyrus has starred as Hannah Montana since 2006, and has also had two US best-selling albums and one chart-topping film. When the book plan was announced earlier this year, publishers Disney said Cyrus would "reveal how her solid relationship with her family, especially her mother Leticia, helps her navigate the spotlight".  "It's finished but you've got a long process of editing and all that kind of stuff, so it takes a while." Cyrus has also filmed Hannah Montana: The Movie, which is due to come out next year. " BBC