Have her check her thyroid.

I don't have any children myself so I can't speak from first hand experience here. I do have two sisters though who both have children and I know their hormones were all out of whack when they were pregnant. How far along is she now? Perhaps after she has her second child, she will be a little more motivated to lose the weight.
I'm sure some of the other girls who have had children will offer you some personal insight. I would say just continue to be supportive of her. When she goes grocery shopping, you go too and try to opt for healthier food choices if she's choosing the not so good ones. You may even want to look into any fitness clubs that offer programs for mom's-to-be. Sometimes being around other women that are experiencing the same thing, will help. Has she been into weight training before?

DJ VENOM,
im with fyre. have no kids so cant speak from experience. just wanted to let you know i aint ignoring your thread

chichy

Thanks Fyre, She hasn't trained to the same level that I have been. However, she did at some point pay attention to her diet. I am not big on putting any pressure on people ecspecially my wife. My diet is pretty squared away and she has the option to eat the same things I do. For some reason she just doesn't.