I thought it was a good sub plot but it didn't go anywhere so it left me wondering why bother starting it because by now she should be dead.
It's been left too long for the MC to be the hero in that story. He's left her in that environment while he's dicking his sister, daughter and/or wife which means he's put that before the girl being raped and beaten on a daily basis. It should have been dealt with there and then, now it looks like an afterthought and the MC looks like a prick no matter what.
How would that go, sorry Sofi, I couldn't stop your junkie mother pimping you out to get abused because I was fucking my married sister ... no hard feelings.