What types of things are 13 year old girls into? A young girl needs your help!!?

I have a 13 year old girl relative and wanted gift ideas for her. Her mum is really strict and doesn't like her having anything that is "inappropriate". I feel a bit sorry for her as she gets picked on a bit at school cause she's so babyish (because her mum babies her). Her mum even rings her on her mobile and recess and lunch to ask if she's ok! So the kids tease her about it. So I want to kind of help her out a bit by giving her a gift that will her boost her self esteem a bit. Any ideas?