Not sure how to help my bff

My best friend is pregnant, due the 22nd. She's been with her bf for 4 years I think. He's physically cheated on her idk how many times and messaged girls innapropriately. He did it again just before Christmas, with a girl I know. He wanted to "hang out". She ranted on fb how wrong it was (no names though) how he has a pregnant gf and looking to cheat. A diffenrent friend told me this happened and wasn't sure if she should tell her. I said I didn't know since I didn't see what was said and honestly sick of hearing about him cheating. I messaged the girl today and told my friend. She said she figured that post was about him and she really doesn't care Cuz she's trying to make things work for the baby. I told her it's not the first time and not the last. He won't stay faithful Cuz you have a baby and won't keep a job Cuz you have a baby (constantly gets fired). I don't want to see her get even more hurt with a child in the equation. She won't listen to anyone, now she's kinda stuck since she's pregnant. They live together and she has nowhere else to go. Idk what to do. I've tried inviting them to church but they have an excuse every time. She won't face the facts that her bf is worthless. I feel bad for trying to separate myself from her lately. Just fed up with the constant crap from him and she doesn't do anything. I don't know how to handle this anymore. Any suggestions?!?!