How old are your girls? If they are fairly young, and you are looking more for a "tea party" there is the Perfectly Princess Tea Party (very pricey, quite a splurge but you get a lot of extras, like a doll) or the Wonderland Tea Party with Alice and the Mad Hatter --
http://www.wdwinfo.com/Just_for_kids/teaparty.htm
But if you have young ladies that would enjoy an afternoon tea in an elegant atmosphere, it would be a lot of fun. The tea room is lovely, and the food was very good. And even though a few people may say discouraging things about taking children there (not necessarily on this thread, but I've read a lot of posts):
1. It's Disney World, folks.
2. They even have a special selection on the menu specifically for children.
3. If your kids would enjoy a "grown-up" tea and use appropriate manners, there is absolutely no reason not to bring them.