Marriage on the Rocks

I have two friends that are having marriage problems and at this point I'm not sure what to tell her anymore. The first couple have been married for 2 yrs and their problem is the mother-in-law. She is crazy and I know her outside of their marriage and I can attest that this lady needs some serious help, medication or something. Like I said B & L have been married for 2 yrs but L's mom is the one with the issues. L's entire family live in fear of his mom and the problem is that he is not standing up to her. He is allowing her to control his marriage and I don't understand why? I know Nick would never do that, so giving her advice is hard because I just can't imagine being in the situation. I have told her to tell L her needs to grow up and relize he has his own family and his mom can't control him but the guy lives in udder fear of his mom. What do you tell someone and seriously how can a person go about having someone with these types of issues commited because the lady won't go in on her own. I have no idea what to tell her but she doesn't what to see her marriage fall apart, they have been trying to get pregnant for over 1 1/2 yrs(they lost their first one when she was 10 wks and have been trying since) and this whole situation has just brought another level of fear, stress and distance between them. I feel horrible and I have been talking to B alot lately about the situation because she has no one else to talk to. I talked to Nick about it and asked him what to do when a person tells you that they are not afraid of death because they currently feel like they are living in hell on earth. He did know either :( So I am up for any words of wisdom that I can share with her and any prayers that you can give her.
Prayers are needed!