Is she arguing with another woman? If so, then they will both be reasonable, see each other's side and agree that they are both right. If it's a man, then the woman is right.
Well it depends on what time of the month it is really, I personally have been known to fall out with myself when in such mental turmoil. Unlike the sound of one hand clapping, the sound of one woman going mental has been known to echo up the high street, down the main street and along the way.