What should I tell my best friend

My best friend has been seeing this guy since May. He isn’t from where we’re from, he lives 25 hours away. He moved away because his ex gf took his two daughters away and needed to get away so he says. He is working up here for a friend but decided he wanted to try to get some custody of his daughters so moved back temporarily to go to court and all that. If it comes down to it, he will stay there so he can see his Daughters and my friend will move with him. She just bought land here and got a job and now wants to move. Also she said she will only move if they get married! Another thing is she found out that he has another child with another women that she found out on her own. I don’t know what to tell her but I think it’s crazy!