The list author says: "My 5 year old daughter loves these stories. The first ones showed up in our Scholastic Book Orders. #3 and #4 I found in the book store. When we got 2 more from the book order, I expected they would be #5 and #6 but it turned out they were from later in the series. It appears that 15 books in this series have been published in the UK and Scholastic is gradually republishing them in the US but not necessarily in order! Hence this list."