OP there's nothing you can do accept suggest that she's still in the cycle of abuse and see if she wants it to end.
A distant friend gave up her marriage and relationship with her Adult children, as well as wider family/friends, for a 22 year old. He came back and forward to the UK and she started to not trust him. He went back home and she stupidly went over to see him. This was after just re-starting contact with her children.
He set up for her to be raped, so he could threaten her with Prison, or to buy her way out. Whilst she was being raped there were his family members, Women as well as Men, who ignored it all. He could see that the Gravy train was coming to an end when people were coming back into her life. Personally I think he had the plan to kill her, or do what he did, all along. He didn't seem to want to settle in the UK.
She's a broken Woman. Her and her ex DH have lost everything they built, he's developed a drink problem, her children can't forgive her and friends find the whole thing too difficult.
She isn't the only one that I know and I've learned that holding a British pp means nothing, it's having the means to pay trouble to go away, that counts, but there's the effect of that trouble that stays with you forever.