 Billingsley was born Barbara Lillian Combes on December 22, 1915, in Los Angeles, California, the daughter of Lillian Agnes ( McLaughlin; 1891-1956) and Robert Collyer Combes (1891-1950), a police officer.She had one elder sibling, Elizabeth (1911-1992).Barbara's parents divorced sometime before her fourth birthday, and her father, who later became an assistant chief of police, remarried.