I know of a similar situation with my friend's mom... I don't think she got totally screwed over, but she was a teacher for years, then stopped working when she got pregnant with their only child, and he supported the entire family. Then 20 odd years later he starts having an affair with some woman in Minneapolis and they get divorced and he packs off to Minnesota. So meanwhile, she has no work experience for decades, she's in her 50s, and she has no income. I'm sure he's supporting her to some extent, but her daughter was already in college, and based on what ljg says she probably doesn't get much. The point is that YOU JUST DON'T KNOW.
Another story-- my cello teacher was married to a guy for decades, and they were a perfectly normal couple and you would have thought they'd be together forever. They retired and bought a bed & breakfast to run in West Virginia. COMPLETELY OUT OF THE BLUE a few years ago, her husband just leaves. I think he left her a NOTE. Seriously. I don't know her financial situation afterwards, but she had to sell the B&B. Again, the point is... you just don't know. People can be very, very surprising.