The neighbor received a notice of termination... terminating the rental agreement "without cause", but she knows why. Her music. Her very loud music in the middle of the night. She came to me asking me if I would talk to my son about it. I had to remind her that I do not interfer in my son's business.
Her usual way of reacting to anyone who asked her to turn the music down was to ignore them. That's what she did when the police knocked on her door... she just didn't open it. She talked to me about it. What she really tries to do is rationalize it. She has a lot of justifications. And she shares them often.
I hope she finds a place that is even better suited to her needs.