Her other early movies include Pabst's Diary of a Lost Girl (1929), Dreyer's Vampyr (1932), and eventually F.P.1 (1932), where she played her first leading role.

After World War II, Schmitz was shunned by the German film community for continuously working during the Third Reich, and it became difficult for her to land roles.

She appeared in supporting roles in such movies as Zwischen gestern und morgen (1947), Sensation in Savoy (1950), and Illusion in a Minor Key (1952), but was beset with alcoholism, drug abuse, depression, several suicide attempts and the committal to a psychiatric clinic.

Her self-destructive behavior and numerous affairs with both men and women further alienated Schmitz from the film industry and her husband, screenwriter Harald G. Petersson.

At the time of her death, she had been living in Munich with a woman named Ursula Moritz, a physician who allegedly sold her morphine at an inflated rate and kept Schmitz doped up while squandering the little funds she had available to her.