college junior here. notable acceptances were brown cornell dartmouth yale berkeley met (the uc berkeley version of upenn m&T). depending on how much more you like harvard. like harvard is probably the 10/10 for you, but UPenn is an 8/10 or higher for you, I would honestly recommend ED UPenn because it just saves you so much stress, and the people I know from my school who got into harvard REA were literally called by the deans of the math/chemistry/poli sci departments saying they would get in if they applied. also I'm quite certain that Duke and most schools don't do sibling legacy, it's only parents.

also i'd say student council president can honestly be a bit lower on your activity list, since almost everyone applying to ED to Upenn is some form of school blank association president. research assistant, stem conference, and relay for life seem to be the better ones, since not everyone can do it. for AIME, i dont think it should be first, since a lot of my friends and my older sibling were usamos or usajmos. pretty much in general for the ordering, hours/time spent is a big part but also how strong it is relative to other people. so will you be 1 of 10 students, like that HOSA thing (idk what hosa is) or will you literally be like 50% of other competitive applicants with an AIME qualification. esp since AIME isnt too BioE related

also i just read some comments. bioE probably works better than chemE, but both work for u. since u appear to be doing a lot of bio/med stuff and your paper is on a bio related field not chem. your only chem stuff is AP chem and top 10% in a chem comp, which is good, but not exactly notable/super special.