Complex sentence: She turned down an offer to appear alongside Mickey Rooney in one of the MGM "Andy Hardy" movies, and went on Broadway, making her debut in the musical "Count Me In" in 1942.
Split into simpler sentences: She turned down an offer to play alongside Mickey Rooney in one of the MGM "Andy Hardy" movies. Instead, she went on Broadway, making her debut in the musical "Count Me In" in 1942.