First, I do wish people would stop using the name Karen like that. It's so sad. I know so many kind and struggling/disabled older women named Karen -- you'd have to, it used to be one of the most common names around -- and they've dealt with so much hardship and given so much to others, and suddenly their name is synonymous with "horrible selfish entitled person". And there's nothing they can do about it. I wish people would think about how rough life has been on a lot of older women, and just think about one you know who isn't rich, just gets by, is always helping her kids and other people, doesn't complain, doesn't ask for help, just tries to stay cheerful, has always worked, and imagine how it would be if that sweet person you know had to put up with this new abuse all the time randomly. It must hurt. Maybe find another way of describing entitled people who make other people's lives hell.
Second, if you can find the neighbor who complained, maybe talk with them about what the problem was. It could've just been a bad day, some major stress, who knows. If they're awful, well, you tried. But maybe things will just calm down.