Hm, her lowest resistance is 75 for lightning, all others are at 100. Can you curse her with the survivor curse? If so, then polymorph will work.
Before Sir_Toejam posted that trick, I used the oldfashioned way and killed her with elemental strike. Used Banish to kill her Death Knights.
Have you got at least lvl 1 in Deadly Gift for the steel scorpions?
Kiya
