Amy:
Take it one year at a time. She is presently happy with her K teacher,she is thriving. Enjoy! A GT program might not give her that.
Did you already look into the next year? Do you know first grade teachers? Can you hand pick them? Would the teachers work with her/you in a regular classroom setting?
I was always the one trying not too look at the numbers, but instead focus on how well accomodated my child was. Granted, I did not know the numbers when he was in K :-)
So my advice - take it one year at a time. Try testing again next year but try really hard to talk with 1st grade teachers and accomodate DD in that way.
It can be very, very frustrating.