She has high expectations of you. Although you say you were straight with her from the very beginning, it does not matter. The fact that you still remained friends probably made her think that she still had a chance to change your mind and become your girlfriend or your lover. It happens all of the time, and not only to you. With men and women, this swings both ways. You thought you made yourself clear, but she's thinking something else. It is so easy to try and think you can fit someone into your life because you want them so badly, but in this case, she now realizes that you are standing your ground. Now, she will have to deal with rejection. Again. And, she's angry. Or, she will keep trying even harder until you give up and make her your girlfriend. If you strongly feel that she could be a friend of yours, try again on your terms. But if the drama continues, and she blames you and says its all your fault that you refuse to meet her expectations, limit your time with her or completely dance away. We are talking about your sanity, here.