You know what sets her off so you have to leave it alone. She knows something is wrong, but she doesn't know what yet. You need to act as if everything is ok for now and let her stew on her own.
I know how bad you want to help. You can't, and she doesn't want you to anyway. You have to leave this alone. Don't sit with her and stare at the tv. Get up and start making some serious changes, be a little mysterious. You have to change too in order to make it through this.
Your daughter has a new friend in your wife. She is in teenage mode too right now. It makes perfect sense.
