Dear InquireWithin:
My heart just fell when I read your story.
Your wife is abusing your children. By leaving her to her own devices all day, you are helping her to do that. Simple as that.
I agree with the above posters. Get yourself a lawyer. Take work off to do it. Take Fetal Alcohol Syndrome literature with you.
PubMed Health - Fetal alcohol syndrome
According to the NIH, binge drinking is more damaging to the fetus than continued drinking at lower levels. Your wife is clearly binge drinking.
It is not too late to stop the damage that is occurring. You can't stop the damage already done, but the baby's nervous system is beginning to mature now, and your wife is laying down tracks in the baby's system RIGHT NOW that will affect your child's ability to live a functional life.
No good parent would abandon a handicapped child, but no good parent would deliberately cause a handicap either. As a healthcare provider who has delivered over 2,000 babies, I can tell you that nothing is more heartbreaking that hearing the shrieking cries of a newborn who, by no fault of their own, has been born with an addiction or a brain damaged by alcohol. Unlike crack, heroin, and cocaine, which are bad enough because the baby has to go through withdrawal, alcohol is worse on the fetus than those things, causing actual mental retardation, and often with physical deformities such as a misshapen head, abnormally spaced eyes, and other physical abnormalities very specific to fetal alcohol syndrome babies.
Your wife will be wrought with guilt if this child is born damaged because of her addiction. How likely do you think it will be that she will want to get sober then? I think the only time you have to act is NOW.
Take off time from work if you have to. You probably will have to. Doing this now may save your baby's life, not to mention your toddler's life, and hopefully your marriage. It sounds like your wife might be better off living far away from a family that only wants to support her drinking habit.
I wish you so much luck. I am so sorry for you. But there is help, and you must get it now.