What does she like to do? My daughters and their friends enjoy going bowling every once in awhile for an afternoon or night out.
For the past 2 years both my daughters have done pizza and a sleepover with just a few (5) friends. Since they are older and more mature, I let them go to the local pizza restaurant by themselves for dinner, then the come back to our house and do whatever. Very inexpensive, about $60 total, for dinner, snacks, and bagel and fruit for breakfast.
You could do a beauty day at a local salon, have their hair and nails done. Or you can have an at home beauty party doing mani/pedi's and facials.