Ugh is right dude... that would be very hard... I would say if you care about her (which I know you do) you gotta tell her to trust you that if she marries him SHE WILL REGRET IT one day. It's not worth it, tell her there is no reason to get married right away and to just wait. Does she want to spend the rest of her life with someone she will be a mother to, or does she want to find someone she can be a wife to? Make sure she thinks about that.

I mean it is her life and her business, so you can only do so much... but yeah I'm with you - I couldn't just stand by and watch this happen to anyone I care about WITHOUT saying something.