Primarily an actress of the European and American stage, she also appeared in many German and Hollywood films. Christians came to the U.S. in 1912 to appear with her parents in a German-speaking theater they established in New York. After making one film in the States, Audrey (1916), she returned to Germany to study with Max Reinhardt. In the '20s she starred in numerous German plays and films, plus a few Broadway productions. With the coming to power of the Nazis in 1933, she returned to America for good, shuttling between Hollywood and Broadway. In films she tended to play supporting character parts, while on stage she continued to find lead roles. Late in her career she was blacklisted after being labeled a communist sympathizer during the McCarthy-era "witch trials."