Most 5yos have trouble writing letters and numbers. For my DD at least, the emphasis was on writing correctly, not so much on counting. But yes, there were kids in her K class who entered not knowing the numbers to 10, or the letters of the alphabet, and who went on to first without having yet learned to read.
Probably too early to tell if you'll have an issue in K. Mine was fine in K, although I consider her to have been a late bloomer compared to many of the kids here. (Entered K generally ahead, but not yet reading.) She also had a teacher who used a lot of play in her teaching, so it wasn't a huge change from the play-based preschool we used.
