I think you just want to kick the can down the road and avoid fighting with your parents over this. It isn’t a “gap year” if you are attending a school where you earn any college credits after HS graduation. And you greatly reduce your chances at a top school by being a transfer student.
That said, what about animation programs at places like USC? You certainly don’t have to attend an Ivy (your sister isn’t far off in her brainwashing comment, there are many other good colleges, and an Ivy isn’t the best fit for every student who could get admitted).