I agree with your comment pretty much 100%... I'm just not sure how I become more accepting. I know that she is done. I accept that she is done. When she slept elsewhere in the house, I didn't care. When she came home at 6am I didn't care. It's not that I didn't argue about it... I genuinely didn't care. When she complained about how hard it will be to afford things on her own I didn't offer one ounce of solution. She goes to her friend's house for hours on end... I don't care.
I do accept that she's done. Maybe I just suck at cutting her off. I don't know. When she starts talking about her realizations of her issues I listen. Why do I do that? I don't know, but I do. At the same time we can be talking about the kids and in two second we're onto some issue she is having.