A) You are the parent- not her.
B) If she is so bored with pre-school, ask the schools to evaluate her learning level to come up with an acceptable compromise.
C) YOU are the parent... she has no right to dictate, make witty come-backs, or try to negotiate the issue.
(Sorry to sound cruel there, I have two girls that went through that phase, and I learned the longer you let them have the control, the harder it is to take it back later on. My son will be hitting that phase soon enough, and I have no plans to let him start trying to manipulate me from what I think is best. lol. Seriously, give in once and it's really hard to keep from giving in on other things that you need to put your foot down on.)