Complex sentence: Her mother suffered from tuberculosis and had difficulty supporting her, so young Dorothy moved to New York City at the age of 15 and joined the Ziegfeld Follies where she was eventually discovered by Darryl F. Zanuck.
Split into simpler sentences: Her mother suffered from tuberculosis and had difficulty supporting her, so young Dorothy moved to New York City at the age of 15. She joined the Ziegfeld Follies where she was eventually discovered by Darryl F. Zanuck.