Yes, my first thought (as a young mother) was "hold up, there are TWO infants in the house, in her care". Does she drink WHILE caring for them? Does she still nurse the 2 month old? This is very dangerous.
I completely agree that if you have a problem with her drinking, then the marriage is in trouble, whether she acknowledges it or not. However, your FIRST priority should be the babies. They cannot be left in the care of a mama who is blotto, or even just a little buzzed. So many things can go wrong!
Normally, I'd say "let go and focus on yourself", but the children's presence in this equation changes everything.
I urge you to speak to your wife's doctor, perhaps to a social worker and even to a lawyer, because this situation could quickly get nasty if one of your children gets injured while in your wife's care.
Keep us posted...