Someone really needs to tell this woman about herself. I would be the one. I would tell her she's obviously mentally unstable and unfit to be a mother. She needs help. Her whole family is enabling her. I would tell her to come get her f****** dog and her kids. She needs to woman up and handle her isht.
If everyone hates me after all is said and done, so what. Your SIL needs to get a grip on reality.
I just want to do what I want to do when I want to do it.