We found the best place to meet the princesses was at a character meal at the castle, we went for breakfast and met Cinderella, Belle, Snow White, Jasmine, and Alladdin. If you don't want to do a meal (and Cindy's can be hard to get) I believe you can see them inside the judges tent in Mickey's Toontown Fair, I think they have a line in there to see the princesses, one to see Mickey and his friends, and one for the villians. Also, Belle does a storytime in the garden next to the castle several times a day, and we've also seen Snow White in Epcot at the Germany pavilion. I'm sure others will have more ideas for you too. Welcome to the Dis! Have fun on your trip!