The daughter of Belgian critic-screenwriter Charles Spaak, Catherine Spaak grew up around European showbiz folk. At fifteen, she made her film debut in Nightwatch (1960). So long as she remained on the continent, she was permitted a reasonably wide variety of roles, ranging from nuns to wartime resistance fighters.
Once she came to Hollywood, however, Spaak was packaged and promoted as just another foreign starlet, interchangeable with Claudia Cardinale, Camilla Sparv, Elke Sommer and the rest of the batch. Catherine Spaak is the younger sister of actress Agnes Spaak (Dr. Orloff's Monster, Better a Widow etc.) ~ Hal Erickson, All Movie Guide. 