I think it depends on whether she does this kind of thing a lot. If so, then maybe she has an unusual idea of what submission means. But if this is very out of character for her, then I think it speaks more to something about that situation - not drinking is very very important to her, or weddings freak her out, or having another slave around made her nervous. Punishment is fine, if that's how you roll, but I think it's more important to figure out why she had this sort of extreme moment. It almost sounds like a fight-or-flight to me.