The little irony here is that at last we have something definitively illegal happening at the Skate park - Faye's basically unprovoked assault on CW.
Ever heard of 'fighting words', Jim? Some states (and, notably, the District of Columbia) enshrine in law the concept that certain forms of speech are, by their nature, provoking an aggressive response and are therefore neither constitutionally nor legally protected.
Corpse Witch just threatened someone who, even though isn't a friend of Faye's, is a friend of a friend
and very much at a disadvantage. Corpse Witch didn't really even have a justification for doing this other than a personal power trip (Did she really have any reason to believe that May would talk? If anything, it is
in May's best interest to remain silent, as Bubbles has already effectively pointed out). Corpse Witch just escalated for no good reason after a long period in which Faye has got a clearer and clearer impression that she is manipulative and cruel, including towards Bubbles, in whom Faye has a considerable personal emotional investment.
In these circumstances, Faye could claim extreme provocation
and acting to protect May from an unjustifiable threat of harm and there are several places in the world where this would not only be considered 'justification' but even 'reasonable cause'.
Of course, we're talking law and this won't go to the law, at least not officially. This will probably be settled privately by the parties involved and witnesses in a manner that predates all written legislation in the United States and probably Europe too.