One more thing.. document EVERYTHING. As inconsequential as something may seem, document it. Get a spiral bound notebook and carry it. Documentation will pay you back a thousand times if things get ugly. And don't tell her that you're documenting. You want her to have NOTHING to back up her side of the story if you can help it.
I would start by documenting what's happened up to this point, with approximate dates & times.
At this point you have to remove emotion from the equation and do what needs to be done.