I would also venture to say the A at AA relates very well and has a lot in common (a strong bond) with other recovering A's. Sadly, this camaraderie can be quite strong. The A is able to re-live the drinking by sharing and listening. I guess it is a wishful thinking to be drinking again. Additionally, the AA group in a way substitutes the old drinking buddies group.
I would not stop her but I would look to protect the child. I would speak with local police and child protective services for advice re this