Agree with the suggestions above, relax, sleep well, eat well, and enjoy. Hope you get an experienced tester. Psychologists who conduct iq tests generally know very well how the mood and mental state of the kids will influence their scores and they know how to build rapport with the kids first and help the kids get into a positive and happy mood.
I also think that not getting into the GT program is not the end of the world. I think you also need to relax. We have been in two districts, neither has GT programs of any kind. But both are top (or near top) districts in their respective states and many students in the districts are very accomplished.
