Its difficult to work with an intoxicated person. I doubt she will even remember most of the event if she was as drunk as you say. I wouldn't worry about unless you go back there to work and she's drunk again and interferes. If that happens, then it's time to meet with her after the fact and clear the air tactfully IF she affected your work.
If not, then let it go. If it was me, I would just ignore her as much as possible, walk away, stay away from her, "be busy" so you don't have to baby sit her.
I doubt you're working there every weekend. Don't bad mouth her. Just do your job the best you can and move on. It's her place and sometimes we get stuck with stuff that we have to learn to work around.
Take her out to lunch after the fact, act as if nothing happened and get on her "great" side. Who knows, you might learn something about her and her disease which could help your future working relationship.
My dad was alcoholic, died from it. Nicest, most giving guy normally and when he was intoxicated even more so. You can't stop her from drinking so learn how to work around it if you go back to work there and she's intoxicated again.