You have tried to reason with her, and she is obviously ignorant to your famiies needs. Contact environmental Health, they will send a letter to them saying they have had several complaints, so it could have come from anyone, she wont be able to pinpoint it on you. I know how you feel as I had this problem in the past, only with music coming on at midnight, it drives you mad. Get in touch wit E.H you have tried to be polite but clearly she isnt bothered about it. People eh!!!!