Hi Karen,
Cinderella's Royal Table serves guests during breakfast, lunch, and dinner. The menus are all different. Breakfast is a set plate meal, but it is all you care to enjoy. You can ask for seconds or thirds on any or all items. The lunch and dinner menu are a set price, but you are given about five or six choices. The entrees for lunch and dinner are quite different. My favorite lunch entree has been the british styled meat pie. My husband usually gets the sandwich choice. During dinner the choices are more robust including items like prime rib or lamb chops. It has been about six months since I have eaten there and the menu could have changed.
Any of the meal you enjoy there, start about the same. As you enter the castle you get a chance to meet with the Cinderella. A picture package is included with the price of the meal.
During breakfast and lunch, additional princess from WDW come by your table to chat with your party. They will also sign autographs or pose for pictures. At dinner, Cinderella's fairy Godmother makes an appearance with some mice friends. There is a short show, but no characters actually come to your table, like they do for breakfast or lunch.
I hope that helps. I would recommend trying to go to one meal at the castle. Your daughter will most likely enjoy breakfast or lunch the most.
All the best
Michelle