Sounds like she acquired a Horror Mark via the spell of the same name. When this happens you have a small, random chance of being attacked by a horror every turn. I don't know of any way to remove it. The event you described has never happened to me in the many games I've played, so it must be rare.
There is no way to remove a horror mark. A vq can probably kill the horror, especially since you are playing an non-recent-patch version if you have a vq pretender for ermor.