The principal has asked me to start with teachers before coming to her, I think that she is encouraging all parents to start with them, not just me.
But, on a hopeful note, I found out that Florida Virtual School, which is free for us, has middle school online classes that might supplement the regular curriculum nicely (and not $$$ like the Northwestern gifted ones we have done) but I needed special permission to put a soon to be 4th grader in a 6th grade virtual classroom. The principal was the one to ask, she said that she'd sign anything like that. So, she "gets" some of it.

Taking into account the wise opinions here, and blending them, it seems that jumping to the principal in only April, after a one hour preliminary conversation with the teacher for next year, might only get me in trouble, and DD, too. Perhaps I will push gently over the summer, by waiting until those achievement scores come in, perhaps if we get into DYS, etc., then having a general meeting with the principal to "catch up" (we did this last summer, it was pleasant but nothing concrete came of it) and start pushing harder.

The principal has been different with DD5, perhaps because she knows us. She asked if we can put her in K next year, because it is such a "sweet year" and maybe skip 1st. I thought that was interesting, but confusing and not really bound by research or knowledge of PG kids.

We moved to this suburb to be near this school because of the dual language curriculum and it totally stresses out my DH when he thinks that he commutes a long distance to work so that we could be here, yet it isn't working for us. Also, the girls are super sensitive and attached to their friends, even though they both admit in quiet moments that they don't really feel kinship except with their parents. So, those are some added details.

I do think, as someone said above, that this is a private school with an expectation of having smart kids, and many of them are probably mildly or GT, but none at all like mine. Yet, the teachers have a hard time even imagining that mine would be so different than these other bright kids. This year's 3rd grade teacher drew a bell curve (and she drew it wrong, it was weird) and showed me that my DD is alone at the top, yet, when I ask for a more challenging curriculum she just doesn't do it. I don't think that they are equipped.

My DH's response is sometimes that we should just move to a real city (we used to live in NYC, so we are snobs here in suburban Florida) - but I read these boards and know that that would not necessarily be a perfect solution, either.