It’s been a while since I have read all three to the kids, but from what I remember they are all really good and continue the story of Elmer and his dragon. I don’t remember there being anything that I needed to edit at all, but as some mentioned before on this forum Elmer disobeys his mother at the beginning of the first book (and she is portrayed as a not very nice woman).
Hope that helps a little!
JoyinIndo