She is technically contagious, but doesn't really use her bite to spread it much. The curse has to have An Effect, but it doesn't specify it has to be /that one/, so she uses her magic to make The Effect just kinda... whatever is needed/wanted/funny at the time. It's her favored way of casting her magic
"Canonically", she's much more bitey than she is prone to eating people, so pretty good odds to just lose a finger or two :3