Good ideas for an 11th birthday party?

Well my little sister is turning 11 but she is quite grown up for her age and she doesn't like things like scavenger hunts and things like that :) She liked the idea of a professional photo shoot with her and her friends but it would of cost about two hundred pounds! She would have a disco but lots of people are doing that and she had a sleepover last year so please, any ideas? oh P.S she would like it if she could invite boys but she does like the idea of something girly like professional make up or something but SO EXPENSIVE! so if you have ideas or know a cheap way of getting something like that done please tell me and if there is a website for it, please post the link :)