I would really get to know her better first (by talking to her alot and doing the stuff she wants to do) before you consider asking her out. I have found that in some situations you end up developing the kind of friendship where you are best-friends and you don’t really want to go out, since if you do and then break up, its never the same. If I were you and I thought of going out with a best friend, I would wait till high school. You have a much better chance of staying together then, and the wait will be undoubtedly worth it. But, if she isn’t going to be that kind of friend, I would hang out with her more, find out if she likes you, and then ask her out if thats what you want.