White was born in Bradford, the only child of a commercial traveller who left the family when she was young. She grew up in North London with her mother, Eva. They endured the Blitz during the Second World War together with their cat, named Luftwaffe. She took her school examinations at Henrietta Barnett School at the same time as German doodlebug attacks, the girls sheltering under their desks if it seemed a hit was imminent.
