Hi, Karla! It's so exciting that you are thinking of celebrating this incredibly special day in such a magical place! Your daughter will have memories for a lifetime!
You are going to have several options available to you - everything from just booking a table at a regular restaurant, to maybe booking a private room at one of the restaurants. Depending on how many people you are thinking of having, you may even want to look at reserving a banquet room and go with a catering package.
Your best bet is going to be to place a call to 321-939-4555. They can help you by explaining some of the packages offered to help you incorporate some of the wonderful traditions of the celebration.
If you decide to just make dinner reservations some place special, you can check out some of the restaurants online by visiting
Disney World Dining Reservations. You'll find some really wonderful signature dining locations, such as Jiko, California Grill, or Artist Point, that might help you make your princess' Sweet 15 practically perfect in every way.
Felicidades - and happy planning!