P.M.
QUICK, read a terrific book by Faber and Mazlish, How to Talk So Kids Will Listen, and Listen So Kids Will Talk. This is a remarkably concise workshop that teaches you how to help your daughter communicate her feelings and needs, and participate in finding workable solutions.
Of course you are irritated and unwilling to put up with your daughter's recent behavior. That information will not help her find a way to deal with her feelings more constructively, however. She may not be able to answer a direct question "why," but with some compassionate listening from you, she can probably describe her feelings and see much better ways to resolve them than fighting.
These communication techniques are so obvious and effective (once we've actually tried them) that it gives us a new appreciation and respect for our children's capacities to deal with their own issues, once they feel supported and understood. I use this approach to excellent effect with my 4.5yo grandson. They will probably work even better with older children.