Three sheets to the wind? That's a drinking term for being totally drunk! I think you mean totally fatigued and "spent"?

You don't have to be a friend to your daughter, I'm sure you know. But be consistent in your love for her. If you say nothing to argue with, she cannot argue. Give positive affirmations. You may have to dig for them, but give her good compliments and nothing "but" nor contrary right now. She wants you to rescue her, but she needs to feel in control I think.