I have just said my dd is whatever grade she would be in by our P.S. cut off dates if I need to say a grade level for anything. She works at different “levels” in different areas at home, but we use the P.S. grade levels for anyone asking/needing to know.
If you went by your P.S. cut off dates, what would grade would she be in? Is that why you registered her as a K when she was almost 5? If not, then maybe you could just tell her you are going to start going by the dates others normally go by for P.S. (or for whatever standard you’d like to use)……when you say a grade level, and maybe explain how grade levels don’t mean as much as just working to your potential whatever that may be. (I know it needs to be worded differently to whatever would make the most sense to your dd if you are really needing to change her grade level on papers.)
I hope that helps a little. Maybe someone who has done something similar before will be able to give a good example of how it worked out for them.
-Kim