haste and recitation spells and strength potions. all characters but one on ranged weapons (magical ammo). the one not on ranged is your beef, armed with his best weapon (hopefully +3 or better)and potions of x-healing. concentrate everything on her. she should not have the chance to cast spells and should die quickly. the rest is a piece of cake...remember, archers don't arch when there's a sword in thier face