McAndrew graduated from Northwestern University and immediately went to New York City to pursue an acting career. She ended up in a bus and truck tour of Half a Sixpence in a non-singing part. She waited tables and other odd jobs, but Half a Sixpence would be her only professional theater job prior to landing her debut film role in 1968, the movie adaptation of Hello, Dolly. She finished filming in August 1968 but for various legal reasons, the film itself did not come out until December 1969.