Originally Posted by
roflcopter666
She gets hit a lot throughout the fight, especially if your DPS is low. Mark of Blood's tooltip reads: Whenever the marked enemy deals damage to a target, that target is healed for 4% of its maximum health.
The Lich's Frostbolt Volley
The Blistering Zombie's explosion
The Blazing Skeleton's Lay Waste
The Abomination's Gut Spray
-theories-
Since you can buff her with Dampen/Amplify Magic, Kings, Spirit, etc. it might also be possible to misdirect or Tricks of the Trade a mob to her.
If that's not possible, seeing how she is attackable / targettable by mobs, you might be able to divine shield (on paladin) and Blessing of Protection (on DK) the threat onto her if you're the last two people standing.