Gertrude Thanhouser appeared in only one Thanhouser film, St. Elmo, according to family tradition. A sketch of the Thanhouser family, prepared by her son Lloyd F. Thanhouser decades later in 1970, noted: "I believe Gertrude appeared in only one Thanhouser release - an adaptation of the old stage play, St. Elmo. She was greatly disappointed when she saw the preliminary runs. Now over 30 and twice a mother, her face and figure had changed considerably in the decade since she left the stage. Besides, she no longer really had time for acting; her scenario writing and film editing responsibilities occupied most of her waking hours."