Congratulations! My DD was moved from K to 1st Grade after the 1st week of school. In 4th Grade, she was also telescoped into 5th Grade Math after the 1st Six Weeks of school. (We did not want to do another full grade skip.) Everything went smoothly. DD's school gave the option of undoing the skips on the front end. Knowing that everything could be changed back seemed to give my DD additional courage. It was an easy transition in both cases. Most of the kids in her grade will think it is pretty cool. Grades were no problem...DD was at the top of the class even with the skip. A word of caution though...At my DD's school in 4th Grade, the girls start to get mean, so you may want to keep an eye out for that as well. (No violence, just exclusionary groups or a snide comment here and there.) I did have some comments from parents that found out that she was grade skipped. I just told them that we did what we thought was best for DD. There will also be a few instances in which her age will hold her back. For instance DD's school is encouraging participation in auditioning for Jeopardy, but DD is too young to compete based on her birthday.
Master of None had some great suggestions. I would also ask that your DD be placed next to some really nice kids in class.
Good luck!
