Excellent books for the seven-to-nine year-old child. The main characters are girls (which is hard to find), but better yet, they are normal, interesting children where gender doesn't even matter at all -- as all children's books should be in my opinion. The stories are fun, interesting, filled with mysteries and mess-ups and just the right amount of naughtiness to appeal to most kids. My granddaughter hung on every word! I would say that the reading level for kids who want to read them on their own is around high seven-year-old to eight-year-old.