Harding's performances were often heralded by the critics, who cited her diction and stage experience as assets to the then-new medium of "talking pictures". Harding's second film was Her Private Affair, in which she portrayed a wife of questionable morality. The film was an enormous commercial success. During this period, she was generally considered to be one of cinema's most beautiful actresses, with her waist-length blonde hair being one of her most noted physical attributes. Films during her peak include The Animal Kingdom, Peter Ibbetson, When Ladies Meet, The Flame Within, and Biography of a Bachelor Girl. Harding, however, eventually became stereotyped as the innocent, self-sacrificing young woman. Following lukewarm responses by both critics and the public to several of her later 1930s films, she eventually stopped making movies after she married the Conductor Werner Janssen in 1937. She returned to the big screen in 1942 to make Eyes in the Night and to take secondary roles in other films. In 1956, she again starred with Fredric March, this time in The Man in the Gray Flannel Suit.