I'm struggling with this one, as this person hasn't done anything to me, but to loved ones, so it's not really my business but I feel so angry on their behalf.
Some months ago my BIL (I'm not actually married but it's the same setup) had money stolen from his house. Specifically a large amount of money which was divided between the piggy banks of his two daughters was missing. There had only been one person around whom it could have been. A woman visits now and then with her two kids to play with his daughters. She'd been outside with them and SIL and asked to use SIL's bathroom so SIL gave her the key.
Time has passed and now money has gone missing from SIL's wallet and from some place inside the house. Same woman after all this time was in the house around the time it was taken.
At first I was aghast they'd let her back in, since we'd all suspected her but didn't say anything as there was no proof. BIL said it wasn't fair on the kids to stop them seeing each other. I did point out there was no need for them to all be indoors but I suppose he feels a bit of a fool as well for letting it happen again so I didn't say more.
This woman always has the most expensive buggy and clothes for her kids, yet does not work. I say the most expensive buggy like she has several, because she does. She said she liked to sell off a buggy after a couple of weeks and get a new one because she 'gets bored' with the same one... Who says that? Nobody does that!
I haven't approached her as it's not my business, but I know when I see her I am not going to be able to walk by without saying something. And that will lead to something else, and then something else until I finally goad her into attacking me and then I'll feel justified in attacking back... ahh who knows if that'll really happen and if there were kids around there's no way I'd let it, but the shouting and finger pointing would definitely happen.
Look I'm talking rubbish but it's really winding me up that she got them twice because they gave her another chance for the sake of her kids having someone to play with.