LW needs to talk to somebody. Like, a therapist. It's entirely possible that her new SIL is, in fact, a greedy spiteful bitch with no redeeming qualities whatsoever, but wow, this level of vitriol can not be healthy for LW.

Also, it does not go unnoticed by me that LW apparently thinks her brother has little to no agency whatsoever. She's the greedy one - he's just "spineless". I suppose she knows these people and I don't, but he's clearly been married to her for quite a while. He must see *something* in her qualities, and if she's greedy, maybe he is too.