This ain't rocket science. Don't drink while breast feeding. Hard to enforce because much of may take place in the home, but it's also difficult to enforce laws prohibiting putting alcohol in a baby's bottle when it's done at home too.
But when you do catch them, as in this case, how do you charge them? What numbers?
if it was illegal and people knew about it, a lot more pissed off dads would call it in, I'm sure.
personally, i'd propose an escalating rate.
BAC of .1, you can't do anything but call Children's services for an inspection.
BAC of .2, you can arrest and get probation and counseling.
.
. etc, etc
.
BAC of .1 or more, you go to federal, pound-me-in-the-can prison.