Billie was born in 1982, in Swindon to Paul Piper, a builder, and Mandy Kent. The eldest of four children, she has a brother, Charlie, and two sisters, Harley and Ellie. She attended Bradon Forest School and the Sylvia Young Theatre School from age 12, and became famous in her teens as a pop singer having 7 top 5 hit singles before she was 20. Billie's first husband was UK DJ Chris Evans
, whom she married when she was 18 and he was 16 years older (May 2001 - May 2007), and though they are now divorced they remain good friends. On 31 December 2007, Billie married Laurence Fox
in Easebourne, West Sussex. In October 2008, Billie gave birth to her son Winston James Fox by emergency Caesarean. In 2006, she released her autobiography, Growing Pains
. However in mid 2007 it was re-released on paperback with new information from the actress. Billie admitted to releasing her own autobiography to counter the release of an unauthorised biography that was coming out at the same time.