You said that he has an extensive history and a criminal past. That would make me think that she knows the truth deep down inside, but she is living in denial. I would assume that she has been doing this for a long time? Probably the best thing you can do is take care of yourself. You can hope that the people around you will see you as an example, and also want to follow suit. If she specifically asked you, then you could let her know. Otherwise, it sounds more like you trying to control him through her.