RORY: You made up these stupid rules years ago about the way the Gilmore women would run their lives and now you’re sticking to them even though they’re crazy!
LORELAI: Oh hey, my crazy, stupid rules are the reason we’re doing so good in our lives. They’re the reason you grew up the way you did, the reason you’re even in this school, and the reason you’re going to go to Harvard, so don’t you dismiss my rules.
The reason Rory is at Chilton is because her grandparents are paying for it, not because of Lorelai. In fact Lorelai broke her usual rules by asking her parents for money, so it’s by not sticking to the “crazy, stupid rules” that Rory is at Chilton.
The Annotated Gilmore Girls 