Complex sentence: She made her stage debut in the summer of 1929 with a repertory company in Ann Arbor, Michigan, subsequently returned to New York where she appeared in a number of Brooklyn-filmed Vitaphone short films and performed in summer stock theatre.
Split into simpler sentences: She made her stage debut in the summer of 1929 with a repertory company in Ann Arbor, Michigan. She subsequently returned to New York where she appeared in a number of Brooklyn-filmed Vitaphone short films and performed in summer stock theatre.