My 6 year old loves these. She moved onto this series after finishing the magic treehouse and then the magic fairies series. These books are probably 3x longer than those. The story is deeper and richer than those others.
We find it difficult to find books at her reading level that are not too mature themed. These are perfect. Nothing too scary, but the plots keep her entertained. She gets super excited to read them. And does over and over again.