Honestly?

[She sighs as she raises one hand to rub her forehead.]

There's no guarantee that Wonderland won't pull in any other werewolves. And Regina and I are working on a means to prevent her magic from being used on this particular werewolf again.

But in terms of stopping her? I'm figuring that out as I go. There isn't exactly a precedent for a witch like her where I'm from.