noisy neighbour - AIBU?

My very deaf neighbour has her Tv next to the party wall. We can hear it in every room at one side of our house and in the front garden.
There was a time you could hear it from the end of the street and in every single room at my side, even with my head under the bath water. That was unbearable.

We've spoken three or four times and dropped her a polite note once. Each time things improve to an extent, at least for a while. The trouble is, it always creeps louder and louder again. I've pointed out that the TV's placement means if it's loud enough for her it's uncomfortable for us, She did move it a couple of inches away from the wall but likes it in that corner.

In total this has gone on over a year, but there have been significant quieter spells.

For a few weeks recently, she was poorly and watching TV in a room at the other end of her bungalow - though we could hear it a little it was much better. However now's she's well she's moved back into the lounge.

It's started up again the last couple of weeks but is quickly getting louder. We had her TV noise for about 9 hours yesterday and 3-4 the day before. The volume was about normal conversation to loud conversation level at our side. I have noise-reducing headphones and play white noise at about 70db to mask it -but it still bleeds through. Long-term, it's a regular thing on Thursdays and Fridays, then it can be every day or hardly ever the rest of the time. I know the longer I'll leave it, the worse it will get. Sometimes up to 15 hours solid.

My main stress atm is that I have a really important event at the end of next week and getting wound up due to her noise will be a real problem. Also I need to work at my PC in the main room affected and it is impossible to think. I resorted to a mobile device at the other end of our home yesterday but this is a real struggle as I'm vision-impaired and all my paper files etc are in the other room.

I've become so stressed over the course of time that I think I'm losing perspective about what is reasonable. Sadly, the quality of my life was so much better when she was ill!

Is it too soon to mention this again to her?