So she'd rather lose her job than risk being patronizing by explaining a joke? Ridiculous. She wouldn't stick to her guns to defend her statement if it wasn't something she believed wholeheartedly. And if it were nonetheless a joke, it should be clear to her now that people just don't get it, so what does she stand to lose by explaining it?
*sigh*
I think having to explain the distinction between a "joke" and hyperbole as a literary tool takes all the fun out of the exercise...