YANBU to think she is an arse. That is given.
However, my uncle & "aunt" (we were never permitted to call her aunt/ie), had a very similar set-up for more than 50 years and were, for the most part, very happy. Therefore, whether she will be divorced soon I don't know.
Personally, I think she talks about her husband as if he were some sort of irritant she doesn't like very much. I couldn't put up with my DH spouting that kind of crap about me & my opinions.