That's tellin' her!

One of the niceties of my current position is that I have an Administrative Assistant to handle all the little annoying details.  It's not the first time I've had an assistant.  I've done my own administrative work enough times so that I do understand what the job entails.  Problem is that my Admin's attitude in a word, sucks.  She mutters angrily under her breath about any bump she encounters.  She expects to be treated like a princess.  She bitches bitterly if I show signs of frustration with her endless personal phone calls, need to run errands to solve one crisis or another, excuses to be away from her desk.  In her defense, she's damn good at her job (when she's actually doing it).  And frankly, my predecessor treated her like royalty and spoiled her rotten (and, so the rumor mill goes, had an affair with her even though he was married with children).  So she's got some reasons/rationalizations for her crappy behavior.

What would you do if you were me?

[Poll #978816]