In terms of content, they contain what dvd reviewers usually define as 'very mild peril'. The format of each book is very similar. Two girls rescue in fairy in danger. There is much 'gasping', and lots of description relating to pretty fairy clothes, together with an abundance of sparkling fairy dust.
For the parent reading aloud at bedtime, there is only one criticism - the chapters vary greatly in length. You may find yourself being persuaded to read another chapter after a very short episode, only to find that the next chapter never seems to end!
These are riveting books for little girls, and as the vocabulary and format is quite simple (with line illustrations on most double page spreads), they should continue to amuse and entertain her when she is old enough to read them for herself.
I give these books 4 stars, not for their literary content, but for the sustained enjoyment which they bring.