Where you close to her parents? That maybe why she’s sharing the news. Personally I loved my MIL and if she was still alive I would have loved to see her. But I understand not wanting a relationship either as I don’t talk to any of my former in-laws.
Does her mom know what is going on? That could be some of it too. Keeping familiar people around may help her not be so confused and it may help her mood.
She may or may not have shared it with the AP. It’s not something to get hung up on. Depending on how close she was to her mom she maybe telling the cashier at the grocery store if it’s thrown her through enough of a loop.
As far as her taking the blame for the end of the marriage, I personally would take it one of two ways. She’s either hoping her kids love her enough to get over this and in time they’ll give her new partner a chance (My guess is they’ll get over this like 99% of kids do) or she’s saying the marriage had been over and she’s the only one who knew. You’d be surprised how often people stay in relationships that are over to make sure they are emotionally or financially secure for what’s to come.
Reasonably close to her parents, but think it's more about her than my relationship with them. And yes her mum knows what is going on.
Don't know if the AP is still on the scene and she would lie about it anyway as she has lied about other stuff.
Her reasons for leaving change constantly and sometimes accepts responsibility and others places blame on me. Whatever suits her narrative at the time. Will not discuss next steps or talk financials, still living in a hazy world where nothing is getting dealt with.