M.B.
I used to work in a restaurant in Denver that did low tea every afternoon (vs. British High Tea). Girls that age loved having their birthdays there. It's so not something the boys would be into, and they get to dress up a bit. You definitely get to feel older, which is a bonus at that age. Plus, there really is a fair amount of food. Most fancy hotels serve tea, and it isn't all that expensive for what you get. Or wasn't the last time I went. I've been to the Ritz and the Rittenhouse, and the Bellvue long ago (the Barrymore room was very impressive). Actually, I recommend it to all the moms, too. It's really a lovely way to steal a little time with your girlfriends, or even go by yourself. And I always add a glass of champagne to my order. Why not? It might be too expensive with that many girls, but it's worth looking into.
Good luck!
Martha B.