YOWHOSOSOS YUCK...
She doesn't get it yet --- that she deserves to be happy.
Ask her point blank, "Are you happy with jerko?" Then look her in the eyes and tell her, "You do know that you deserve to be happy, don't you?"
Then ask her, "How would you feel if you had a daughter and this is how he treated her?"
She needs a good friend, but she's sucking you into her misery. To be or not to be, only you can answer. If you can't ignore it and just listen when she needs an ear, then you'll have to walk away until she wakes up and understands her own worth and takes responsibility for her life.
Can you get her to go counseling by herself? Get her to quit worrying about what jerko does and just focus on what she does and how it makes her feel.
It's crushing to watch a loved one devalue themselves and live in such ridiculous circumstances. Maybe she'll find a love strong enough (maybe a single man, not married) to help her pull herself away. Sounds like she needs male attention to feel important.
Best wishes to you both.