Basically, what
>>5020 said.
>>5016>What could they possibly do to you?There are thousands of ways people can make life a hell for you in a circle of people if they have more power than you inside it. It really depends on how much of a bitch that person is, and from what we can read from OP's intel, this one is a big one.
>>5017>Grow a pair, op. If somebody is giving you a problem, tell them. What could they possibly do to you?This only makes sense if you have more power than them when you "grow the pair". If you confront somebody who is stronger than you or in a better position socially, you will only make a fool out of yourself and will become the target of hate and mocking or even violence in some cases (depends on the person).
All of this supposing you actually are shy/reticent/low-profile/whatever fits the classical /n/profile, and the other girl has actually power inside your social circles. If in reality you don't give a fuck about people and this "friend" (or she doesn't have any say in your world), by all means do this. Do not let yourself be stepped on.
Now, to OP: Unfortunately, you didn't seem to know about our rules. Underage users aren't allowed on this site (we're +18 for a variety of reasons). Next time play it smart and ignore age questions.
I'd paste an IRC channels or something in case you wanted expanded advice, but since you're underage and female, that's a terrible idea and the ideal excuse for people to call me (or anyone joining that channel) a pedophile, so sadly, that won't happen.
Anyway, in my opinion you should cut out your relationship with this girl. You obviously aren't in for what she wants off you, and she acts like a bitch to you, so yeah, you aren't really "friends". Do not hang out with her, if you end up being with her in some project or something, ignore her stupid comments (i.e. do not rebut) but don't treat her badly, and keep your distance (i.e. work with the other people in your group). If after a long while she's still like this, yeah, talk with other of your friends and see what would be the better approach. What do your other friends think? Should you call her out? Can you gang up against her and talk about her shitty attitude with your other friends supporting you? This is like rule #1 in winning anything socially related. The more people at your side, the stronger you are. The stronger you are, the more your opponent will have to yield, if they want to stay inside the circle.