Zoso, I think you are wise to take this stalking seriously and taking legal action is the right thing to do. If she lives anywhere near you, I would also make sure I had a secure alarm system in my place and perhaps even security cameras.
The only way to stop a serious stalker is to protect yourself and do what you can to prove what they are doing and then have them arrested.
I am sorry you are going through this. It is no longer about your "relationship" that has been over for a long time now. It's about a sick mind stalking you and you must protect yourself against a dangerous person.
And...I hate to sound like a bad movie here...if you have a new lady in your life, or even if you date, she may need to use caution as well to ensure her own safety.
Stay safe, Zoso, I hope she stops on her own but if she doesn't I hope they can arrest her and make her stop.
Hugs