Her father, Reginald Michael Bloxam Hallward, was an architect and author; her mother, Jeanne McDougall, who used the stage name Jean Grahame, was a British stage actress and acting teacher.
Hendes far, Reginald Michael Bloxam Hallward, var arkitekt og forfatter; hendes mor, Jeanne McDougall, som brugte kunstnernavnet Jean Grahame, var en britisk teaterskuespiller og skuespillelærer.