Calling the cops and filing a police report is the dumbest crap I have ever heard. She put her hand as a holder so a perceived stranger wouldn't just walk on by. If you want every neighbor to hate you and have zero ****s about someone who does break into your place, call the cops. Guarantee you won't be ringing in any friends without the cops being called on THEM.
From past experiences, i can for sure tell you that you(or the old lady in this instance) never, ever, ever touch someone. You can extend the arm as far as you want but never interrupt the path of someone, no matter what. You are better off to go and tell her that she will be reported to HOA/Police for tresspassing unless she can identify who the girlfriend is and where she lives. The minute you put your hands on someone is when you are in the wrong.