Did you profess and get shot down? If not, and you're thinking she doesn't like you back because of obscure comment ("You're such a great friend!") then have a more direct conversation about it. If direct conversation happened, and you know for sure, then I'd say give yourself some space. Unrequieted feelings can grow into some pretty big resentment that can hurt the both of you, so it's up to you whether or not you can stay friends.