There are many great suggestions on this thread! My D26 seems very similar- especially in wanting a smaller, collaborative LAC- she’s applying to a bunch. Her older brother attends Brown and loves it. If your kid is ok with a bigger school, it’s definitely one to check out- not a pressure cooker at all.
From my D26’s list, I would check out Conn College (free music lessons through the music dept for all students and seems to be very inclusive), Wheaton College (great likely admit for this type of kid) Vassar, Brandeis, Bates, Dickinson in PA, and Bard might be another nice target/likely. Follow schools on Instagram to get a feel for their culture, and google what percentage of kids are in fraternities and sororities, too. Swarthmore is a great school- my D23 absolutely fell in love with it- but it’s definitely more of a pressure cooker environment than the others listed.