Pancreatitis and alcohol. She was most likely told to stop drinking. The gall stones certainly can add to issues here. My ex had the same problem, and because he would not stop drinking he developed chronic pancreatitis which continued to affect him after he became sober eventually causing him to become a type 1 diabetic. Not trying to scare you here I certainly am not saying that will happen to her, but I can tell you that if she has had one attack another is most likely going to occur again if she keeps drinking.
I suspect that her becoming and angry drunk after 1 or 2 is really her becoming an angry drunk after 7 or 8 or 12. In other words, as much as you think you are monitoring how much she is drinking you aren't. Hidden bottles are a bad, bad sign, and a red flag that she is drinking far more than you know.
As to your child - please do not fool yourself that she would not ever do anything harmful. While sober I am sure this is not the case. I'm also sure you wouldn't hire a drunk babysitter. No drunk intended to actually do anything harmful on purpose, yet they do often even though the intent was not there.
Education about the disease will be very helpful to you, as well as attending Al Anon.