Prior to Patch 6, you could fight her at her hut which was where you were supposed to find out that she was a Hag. If you sided with Mayrina's brothers outside the swamp she will get pissed off at you for even going to her Teahouse. And it's there where you, the player, is supposed to see her true fugly form. She'd attack you and that was supposed to be a fight you can't win as she'd outright run away from you. But, her "old" A.I. seems to have been broken after Patch 6.