Tried taking advantage of her weakness to bondage play *hint hint*? Wiki states she has a -25% status resistance against restraints.
Granted, at some point she becomes unbeatable, but that's simply because of how the Labyrinth works (hellhounds becoming stronger every time the player wins, or escapes from a fight), but I can usually fend her off 3 - 4 times and I didn't get too crazy with level farming.