Does she have the right to search through my Facebook profile?

There is this girl that I used to like but I stopped right after I found out that she was an attention whore, user, and a fake. She never goes away and it is so annoying. My friend and I were backstabbing her through Facebook messages but she somehow found out that we were doing it and since she found out, I admitted that we did. Now she is concerned and keeps trying to get into my Facebook account but since it is mine, I do not grant her access. Do I have the right to not let her see what we put about her? She will not get away from me and I feel like I am being harrassed. Can I report her to the police? I don't want her reading our backstabbing.