Halfway through my kindergarten year, they moved me to the 1st grade classroom (it was going to be 2nd, but I would’ve been in my older sister’s class and they didn’t want to do that to either of us). So for my entire life I’ve been basically lapped in age by my peers in terms of getting my license, driving past the curfew for minors, turning 18-- my two best friends will be 21 next month before I am 20.
I am really just barely a year younger than my peers and it is a real PITA. Doable, but any bigger gap would be kind of terrible.
I also don’t think 16 is ready for a full year away at college.
Would recommend changing schools or trying DE until the time comes, could even try online courses in classes she’s interested in. Get more involved in EC’s if she has free time.