Complex sentence: She had acted on the stage previously, being a Vaudeville singer at age fifteen and her first film was "The Glory of Clementina" (1922), and her first starring role was in "The City that Never Sleeps" (1924).
Split into simpler sentences: She had acted on the stage, being a Vaudeville singer at age 15. Her first film was "The Glory of Clementina" (1922), and her first starring role was in "The City that Never Sleeps" (1924).