This was a really cute book! It was a really quick read, and took me less than an hour to finish, but I think it'd be perfect for kids in elementary school. I found it in the back of my shelf yesterday, and I have no idea where I got it or how it got there, but nevertheless, I decided to read it since it was there. And I was very pleasantly surprised! Although it would be perfect for a small child, it did have some deeper underlying themes regarding bullying, loss, and friendship that, I think, make it a good book for parents to read with their kids.
One point I'm still slightly confused on is whether this book was based on a true story with the letters being actual ones between the author and a child. I first got this suspicion when I realized towards the end of the book that the author's name was Sally Grindley, but aka D.J. Lucas. I tried looking this information up but couldn't seem to find anything, so I suppose that it's left up to the reader's imagination.