K.N.
I was really funny about anyone drinking in front of my kids for a long time. All it really did was make everyone else miserable because I was making a big deal over nothing. Mind you, I don't drink but a few drinks a year to begin with, but so what is once every few months my kids see someone have a beer or two? There is something to be said for demonstrating that drinking can be done in moderation without people getting drunk.
(and my walls and baseboards may be clean, but i haven't cleaned under my fridge since we replaced it over a year ago, lol) I think she just wishes you were more like her and taking care of her little boy the way she did, mom's are like that.