Carter was born Helen Rickerts in New York City, and her family was of Scottish descent. She first studied at Columbia University, studying for a teaching degree. During this period she worked as a fashion model, which led to her becoming a cover girl. She was offered a film acting contract by producer Leonard Goldstein, which led to a brief acting career. Her first film role was Time Out of Mind in 1947, which starred Ella Raines, Eddie Albert, and Phyllis Calvert. From 1947 to 1953 she would appear in thirteen films, during which time she also worked as a model. In 1948 she appeared on the cover of Life Magazine.