Douche Dilemma

The Douche had his girlfriend call and leave me a voicemail. They miss Lex. I'd take that a lot more seriously if she wasn't so audibly inebriated. Why would you make that call while you're drunk? They're only proving that we've made the right choice.

Itty Bit wants to see the girlfriend and her sister. She does not want to see her dad. 

I'm trying to figure out a way to make this happen. I've explained and Itty Bit fully understands that if they get caught going behind his back, all hell with break loose. Not for us, but for them.

She's expressed to me that she's worried about them. That he may hurt them. Especially her baby sister. I think her concerns are valid.

The Douche always has her phone. He monitors her Facebook account, which means he can read her messages. He's done the same thing to her as he did to me. She is completely isolated and powerless. 

What sucks is I don't know how to fix this for Itty Bit. I don't want to put the girlfriend in danger. I don't want to make things harder for her and her kids. This has to be navigated extremely carefully. 

Part of me wants to rescue her and her kids. Plead with her to leave him. But when she had him arrested for hitting her, she turned right around and bailed him out of jail. She's already shown her insecurities and the likelihood of going back to him. I don't understand it, and I can't fix it.

Any suggestions?