She was born Rebecca Jayne Atkinson, the only surviving child from her mother's first marriage to Paul Atkinson. Her parents divorced in 1978, and her mother remarried three times, to David Sowden, Steven Callard, and Jon McEwan. As a young actor, Rebecca was credited in early roles as Rebecca Sowden; she changed her stage name to Rebecca Callard following her mother's 1989 marriage to Steven Callard.