Haworth was born in England. Her father was a textile manufacturer, her mother a trained ballet dancer. Haworth received in their youth also a ballet training.
Haworth, petite and blonde, made her first film at age fourteen: Otto Preminger's Exodus. After three films in France and other exposures to Preminger 1966 it belonged to the original line of the musical Cabaret, for which she was chosen from among 200 applicants, but initially very modest critical acclaim, the role but overall almost two years en suite played. Following this stage experience, which remained their only role on Broadway, she starred in several horror movies before they took over in numerous television series by the end of the 1970s, guest-starring roles. Since then, it was barely visible.
Haworth lived since the mid-1960s in Manhattan, New York.