I’d definitely put Cal Tech, MIT, and U Chicago in the top rank. Beyond that I don’t know enough to say. Back when I was at Wash U there were definitely a few “Aunt Becky’s daughter” types, mostly undergrad business majors (also plenty of really smart people so don’t let that scare you off, plus that was 30 years ago, but it would have been possible to graduate without being the most diligent student).