Hi, Kerri!  The most popular dining experience at Walt Disney World is probably Cinderella's Royal Table, which is located at Cinderella Castle at the Magic Kingdom.  It's a must do for many Moms with princesses - myself included - and it tends to book very quickly.  You can have breakfast, lunch, and dinner there with various princesses at each meal.

My favorite princess meal is at Akershus in EPCOT.  The Storybook meals there, you will again see a variety of princesses, but I prefer the food options there and I like the restaurant itself.  You can find pretty accurate menus at allears.net if you need them to help you decide.

Cinderella and her stepsisters usually appear at 1900 Park Fare at the Grand Floridian.  I haven't seen her with any other princesses there, and she is only there for dinner, but I love any excuse to go visit the Grand Floridian and do a little shopping!

Characters are subject to change, but these restaurants have for many years done these princess meals.  So now it's up to you to decide which one works best for your girls.  You may even see me with my own three princesses at one of these meals during the same time!  

Have fun planning, Kerri!