I would say she's absolutely right. DS9's school had a meeting for parents of "gifted" students a couple of years ago (probably since then too) and the principal told us that there were about 30-40 kids in the school (k-12) who were on the "watch list", but only three that were really "up there", of which DS was one.
In my experience, GT and AP type classes attract bright kids who are overachievers, but the really "up there" kids will be found in Knowledge Bowl, Speech and Debate, Chess Club, or hanging out in the art room during lunch. YMMV, of course, and it could well be the chemistry lab or computers, it just depends on the particular bunch and the specific teachers involved. Those kids may indeed be in the GT or AP classes, but the classes as a whole will not be particularly heavy with them.
I would add Destination ImagiNation, but we've had three different methods of determining who is in that in three years now, so it depends on how the teams are made up.
