She doesn’t do anything. Sure, she teleports around and does fancy looking filth rings, but she does no damage at all even if she does miraculously teleport to where you are (which she never does). I’ve been checking the combat log to try to get her name (because I don’t know that we’ve seen it anywhere else) and I can’t get anything to come up no matter how much I let her “attacks” hit me.
From the combat log you can clearly see the son is Alexandre and the dog is Tyberius’s Hound of the Final Days. Must be the full AKC registered name. Of course we can see the healthbar and name tag for Elisa.