Well, if you're young, it changes (regardless to whether you are a girl or a boy. Boys voices change much more drastically, but girls voices change too). However, you could go see a vocal coach and ask if they could tell you. They'd run a few scales with you and be able to tell you. The more you warm up your voice, the wider your range will be (but it has a limit. To find out your limit, you'll need regular vocal coaching). Good luck!
