Hi Kimberly,
All of you kids sound extremely bright. Your youngest seems academically talented in addition to highly intelligent.
My kids also knew their letters, numbers to 100 and shapes by 18-24 months and could sight read simply books before three, but neither ever showed an interest in workbooks. Actually, I don�t recall their writing before three. I would definitely encourage you to provide your daughter with the workbooks she enjoys (and worry about the school mismatch later).
Another suggestion for you, that my kids enjoyed beginning at ages 3 and 2, are K and 1st grade level computer edutainment games.
