Appearing in bit parts in several of the studio's more successful films, Morris was signed to a Metro-Goldwyn-Mayer contract in 1941. For one of her early film roles, Cry 'Havoc' (1943), she affected a British accent. Her next picture was the well-received drama The Human Comedy, which featured a star cast, headed by Mickey Rooney, Frank Morgan, James Craig and Marsha Hunt. Morris' role was Mary Arena; the girlfriend of Van Johnson's character. The highlight of her career, however, came in 1945 when she starred as the doomed Ingeborg Jensen in Our Vines Have Tender Grapes. Other screen roles included Someone to Remember (1943), Pilot No. 5 (1943), Rationing (1944) and None Shall Escape (1944).