What to do in this situation?

A good friend of mine recently decided to reconcile with his ex, who is the mother of his children. He went to court last year for sole custody of their children and won, being that she was in jail and wouldn't show up to the previous court hearings to fight for her children. He proved to the court she was unfit, proved neglect and abuse that occurred during their time of trying to work it out before she went to jail and he was awarded sole custody, and once she was released from incarceration, she was ordered to pay child support. Well, they reconciled because she has claimed to "change", when in reality, she has only gotten worse. What could happen to my god kids if the court found out about this? And the child support office calls him asking him if he knows where she is so they can get her. He lies to them saying he doesn't, but she is currently living with him. Since they have been together, which is only 2 months, she has already been to jail 4 times for Failure to Appear and Contempt of court, and changed her address to his. Will he get in trouble for this and/or lose the kids? These are my god kids and I don't want to see them in foster care. I asked this question before, and I will add that he does leave the kids with her during the day while he works due to the fact that day care the kids went to refuses to take the kids back due to this issue. No one, not even his own mother, has really seen or spent time with the kids since he got back with her, and everyone is basically saying they hate the girl and they hate he is doing this, but they have to "support whatever decision he makes". 3 weeks ago, because of her, he almost tried to kill himself and was put on 48 hour psych hold. I love my god kids. What could happen once the court and the child support office finds out he is now back with the woman he claimed to be unfit? And is there anything i can do? Because he made a horrible decision by thinking simply because she is their "birth mother", he needs to make it work with her. But at the end of the day, my god kids are gonna pay that awful price. Please help!