I would throw Emma Willard (all girls, Troy NY) into the mix.
Also, if you haven’t read some/all of this thread that I started back in the day, you might want to…
http://talk.collegeconfidential.com/prep-school-parents/1174214-one-family%C2%92s-bs-search-and-application-process-%C2%97-start-to-finish-p1.html