We're going in December for my daughter's 16 birthday, and she chose to eat at the castle for dinner on the night of her birthday. I ate there for my 50th birthday, and was glad I did. They decorated the table, brought out a special dessert, and we were seated right by a window, so we got to see the fireworks! Her other top two choices were the Cape May Buffet at Beach Club or Le Cellier at Epcot. You'd have to look at the menus to see if there are enough choices for your daughter since she doesn't eat meat.
Good Luck!