My DD at 3.5 ONLY wanted to do meet and greets. We met every princess every day. She even wanted to meet the White Rabbit and the Aristocat even though she'd never seen the movies. She wanted to meet and get her picture taken with anyone and everyone, but especially princesses.
At that age they don't care about rides as much as they care about meeting princesses. If this trip is for her I'd plan on meeting as many princesses as you can handle each and every day. Anna, Elsa, Cinderella, Rapunzel, Ariel, Belle, Tiana, Merida and Jasmine at MK. I'm sure your daughter would rather meet them over and over than do a ride.