You are a very qualified student based on all hard stats which is great news and a testament to all your hard work.
The bad news is that roughly half the kids (if not more) applying are similarly academically qualified. As you know Brown’s acceptance rate even in ED is far less than 50% meaning some great kids don’t get accepted.
The differentiation amongst these students are the “softer” aspects of the application like LORs, essays and personal statements. Hard to figure out what makes a candidate stand out but the cohesiveness of the students narrative, potential contribution to the Brown community, and your potential and desire to have “impact” post Brown seem to be very important.
Wishing you luck! FYI you should also be aware the Vassar and Brown are significantly more difficult acceptances for females versus males so please consider your likelihood of acceptances against this historically skewed result.
Lastly, my son went to Brown and I attended Vassar so please let me know if I can offer anything specific.