Give it one last shot. Sit her down one day when you're alone and ask her straight out "how do you feel about me?" if she can't give you an answer then i'd give up. It's not worth it. At the end of the day.. you'ver made the first move and if the feeling was mutual then she would've made the next move. I don't think it's gonna work but give her the befit of the doubt. People make mistakes... not gettin with you may be one of hers