The options are kind of limited aren't they?

Beyond shaming her publicly (which HER actions will accomplish much more than anything) I can't really see any good course to take.

I am pretty sure, though, that if you keep your cool and maintain your dignity she'll look even more like an idiot. People will see that she's acting like an idiot by taking things too far and will respond badly to her. It may be a good idea to keep a very trusted female nearby that doesn't think anything of putting someone in their place. That way, she can act as your surrogate if need be.

I'm sorry Magnus, it's all I can come up with short of the unthinkable.