I think you have a great chance for Princeton (or any other top school)! I just graduated from college (HYPSM) and my stats and ECs when I applied were pretty similar to yours. Just make sure your essays are in shape and that you tell stories about your experiences in a way that highlights your qualities (ie. if describing your passion for art, you might tell a story about a time when some work of art didn’t end up as planned and how you learned from failure or something like that). And since your sister went to Princeton for undergrad, obviously ask her for tips specific to Princeton.