Born Marlene Aloisio in Detroit, Michigan, Willoughby chose the surname "Willoughby" for her professional work after someone called her "willowy" due to her lithe, 5'-10" frame. She followed her older sister, Jacqueline Carol, in pursuing a career in show business. In 1969, she appeared in the controversial Lennox Raphael Off-Off-Broadway play Che! Other theater roles followed including the Obie Award winning Dracula Sabbat, Fuck Mother and Keepers of the Hippo Horn. She also landed parts in mainstream fare such as No Place to Hide (1970), Up the Sandbox (1972), I, the Jury (1982) and Trading …