If they thought our DD would be a better fit socially and academically with their elementary school students, they have no issues with her moving up there at any age, any time.
we didn't realize how lucky we were with our Montessori pre-school! they moved DD (then just turned 2) up to the Casa room when her friends moved up - essentially a year early. they literally said to us: she's ready, so she's going. it was such a simple solution and even though she ran out of curriculum by the time she was 3½, she had some wonderful years there.
i honestly wish our Montessori could have gone on forever, rather than stopping at K. this year was truly horrible - and the carefully-chosen private school we scrimped for didn't solve anything. they were so dogmatic - telling me repeatedly that DD hiding her skills/having nightmares/being depressed/wanting to die was no problem - you know, because she was already beyond grade level. er, no.
so i'll second Mana's suggestion to check out Montessori-style pre-schools - the great ones are really great!
