Irie,

At your daughter's age it most likely won't matter a great deal whether she stays with her age group or advances one grade. I'd be most concerned with having her in the best (most optimal) academic and social environment. Moving up or down one year during the early elementary school period isn't going to have any significant adverse long term effect if that move places her in the academic and social environment she's most comfortable in.

My oldest daughter started kindergarten a year early. It was the best overall decision. She was slower socially, but adapted so to speak in a short while. However she was never challenged academically until she took honors physics in high school. She finally met academic challenge when she entered a small private college where half her classmates were from private prep schools. Unfortunately she never fit in socially as well as a parent would wish. That wouldn't have happened if she had started school one, two, three, or four years later. One of the perils of genius is being a social misfit during youth. When she was 5 she was going on 16, when she was 12 she was going on 26, etc. But not fitting in until you're at Smith or Stanford can be a good thing in the long run.

Good luck.

Sincerely,

Salmo g.