Oohh do I get this post! I've had this on going for over 1 year now. I have tried everything I could think, being kind, assertive, didn't work. Like yourself my DH used to have more luck but not anymore.
It's truly truly awful. I have been in tears, the chest tightness, I get it. I have just been speaking to the housing association who are going to serve her with a stage 1 warning, and the council installed a noise machine, where they caught her, and served her with a notice, next step would be a 2 stage warning and then court. I don't care how it makes me look, or what she says, I'm fully well intending to go through with this! As history shows me, she is not willing to change. No matter what I do, but I know I have tried everything, I have been reasonable, more than reasonable. If she continues and they have to seize her equipment, he housing team will go for repossession of her property.
Both me and partner love our house, it's in the perfect area, and don't want to move, don't see why anyone should have the power to drive me out of my house.
The common misconceptions, about the times are so wrong, many councils work to the rules that if it effect your daily living and causes you a nuisance, no matter what time of day, it's a noise nuisance. ( Take a look online) I've even made noise recordings on my phone just to prove to myself it's not all in my head and I have a point, no matter what she thinks.
I find the lack of support is tough, very tough. Even worse as the neighbour in question has friends who support her, fully, who live on the same street!