hopeful4--did you and your daughter talk about what is stressing her?
I don't know if this will help, but this is what I used to do. When they got snarky, it would pull them to the side and say something like this: "You know that one of the rules of this home is that we don't get to speak disrespectfully to each other--but, you ARE allowed to speak. I want to h ear what is o n your mind--so, I am going to sit here with y ou and listen to anything you h ave to say (whether I agree with you or not)."
This did wonders toward diffusing their raging whatevers.
dandylion