That's not your job to prove a crime was committed. You just report the crime and the police investigate. Then turn it over to the prosecuting attorney. Then that attorney (county attorney or DA) will decide whether or not to file charges.
If you can set up cameras on your residence then do so. If the camera is at an angle to catch where your car is parked then do it. Then just avoid her and her kids. Let the police handle it. Otherwise if you keep letting them get to you, you're gonna end up doing something that you regret or gets you in trouble.

