She blackmails you, so you post here saying you are thinking about going to the cops. Is this your way of trying to scare her into leaving you alone. I think this post was more for her to see to make her think you are going to out her out to everyone.. If you're not going to say who it is then you should have never posted to begin with. 3 pages later no info has been given out and Im sure there is alot more to the story..
Hate to say it but even if you do out her there will still be some guys who will see her. this post will hurt you more because what female is going to want to see you if you are willing to call the cops. There are other ways to handle this IMO