For some reason, OP, I was thinking "6" = first. (Don't ask me why sicne I know most K kids end as 6yos).

For K, yeah, it's pretty rare to be able to read a real chapter book of any kind. DD was reading easy chapter books in K (mostly things like Puppy PLace and Rainbow Fairies, though she also delved into things like Judy Moody and Ramona; she was not at a Harry Potter level) and that was pretty unusual at her school and in our peer group. By first, though, a few kids were reading chapter books.