When @gardenstategal l pages me, I show up!
@mom2boys123…I don’t know if your kid’s goal is to be recruited/fence at NCAA level, but if you look at the rosters of college fencing programs, you won’t see many boarding school grads. I think this is largely a factor of fencing being a club-based sport. It’s not like playing hockey at Shattuck-St. Mary’s.
When my daughter was considering BS (our local public was unappealing and she wanted a change from the K-12 private day school she had been attending), we tended to focus on schools that A) were close to clubs with strong coaches in her weapon type; B) schools that were flexible about her schedule (training and competition). This knocked SAS out of the running pretty early on, despite our older daughter being a grad and us LOVING the school. Some people thought we were silly to prioritize sport that much, but it all seems to have worked out in the end… 
The Masters School in Dobbs Ferry, NY is definitely worth consideration if fencing is that important to your kid. It has a scholastic fencing team, but more importantly, gives you easy access to the many top clubs in the NYC area (and a choice of airports). They were also very flexible about my daughter’s competition schedule — which at the time was basically all the NACs, regionals, locals, and an occasional international.
George School in Newtown, PA is also worth considering…as it is close enough to Princeton to train at TigerZ (which is run by head coach of Princeton U). It’s also close enough to NYC to get in for training (open bouting at FC or NYAC) or competitions.
If fencing is truly important and college recruitment the goal, I’d check out the “The Only College Fencing Thread You Need to Read” thread in the Athletic Recruiting sub-forum.