She is only repeating her momma's lesson--she never said she followed the advice.  Of course, it is a rhetorical ploy: "momma" never said the height of ignorance is to accuse another of ignorance.  The very concept is ridiculous.  Would Stephen Hawking be the height of ignorance if he told me  I am ignorant on the subject of quantum physics.  Of course not, he'd be stating a fact.  Calling the uninformed, particularly the willfully uninformed, ignorant is not to be ignorant, it is to be honest.