This is definitely a book for a younger audience, but I enjoyed the story. I enjoyed the reality of the characters. The truth to their circumstances. I think there are lessons to be learned for kids on best behavior, on holding back judgement, on accepting others, on how others may see our behavior despite what we think (remember the old adage, "If you think you are humble, you aren't.")
Sorry, since I don't have kids, I can't really tell you what age this is appropriate for - but best guess (from my reading habits as a kid)? I'd say 7 and up.