Retaliatory music that's gloriously annoying, when she finally puts the ukelele down. I don't know if you have a disturbing the peace curfew where you live but shutting it off at precisely that moment might drive the nail down harder..... Try this: [link]
My neighbors are downright losers and worse. My evil eye is pretty spectacular at communicating displeasure.
At my apartment I had the landlord from hell. Outlets that would work one day, then the next not and the same with light fixtures. Heating and air conditioning that would never work when you needed it. When you put in a work order he would charge over 100 bucks on average for the repair that was "our fault" for shorting the wires our blowing the breaker which was bullshit. And then he claimed I never paid my rent, which was also bullshit because I looked at my account and saw he accepted my check.
My current neighbor right across the hall from me is an electrician. Every time his outlets didn't work he fixed them himself. And it was always the same wire. My neighbor who refused to pay a nickel to my landlord accused him of sabotaging the building and a variety of other safety violations. Nothing happened afterwards until I moved out. I then later saw a huge expose on the Seattle Weekly about the landlord and his crafty ways to over charge everyone who lived in the building.
My neighbours walk their dogs in our backyard because they think it's just a random area of trees. 3 acres of land and it looks like a bloody forest. The other day I shouted "GO GET MY RIFLE!" and they never came back again.