She should have called the cat Deathbringer and the sword Snookums. It would have been great. You could be all like "And now I slay you, foul demon of the nether egions with my mighty blade of smiting, SNOOKUMS!!!" and it would rule.
EDIT:Also, if you would use it to kill the undead, wouldn't 'Re-Deathbringer' be a more fitting name? :/