I feel for you, but I think you are right about the best solution to be to house your snakes elsewhere for a while until you move. Even if the snakes were written in the lease, your landlord and/or neighbor could make life unpleasant for you if they decide to.
I recently had it pointed out to me why some people do this, and at least in some situations it makes sense. It is a scary thing in today's world to confront a stranger about anything. You never know how they are going to react. Considering how much your new neighbor apparently fears or dislikes snakes, she probably thinks the fact that you keep them is proof that you are insane, or a devil worshipper, or who knows what. While I still don't think she took the best course of action, looking at it in this way at least makes it understandable why she would make that choice to go behind your back.