Born Dolores Loehr, she was a musical prodigy who played piano professionally by age ten; her first film appearance was at age 12, as one of a group of students performing classical music in the background of They Shall Have Music (1939). In her next film, another music-oriented production, she played piano and got a few lines of dialogue, following which she adopted her screen name and signed a long-term contract with Paramount. She underwent intensive drama coaching, then made a big impression as a precocious teenager in The Major and the Minor (1942) with Ginger Rogers. She played a number of juvenile roles; as she aged, however, she had less luck with adult leads, and appeared in a succession of standard ingenue roles. By the mid '50s she effected a successful transition from movies to TV and the stage, being especially busy as a TV actress. She died of a stroke at 45.