I read this selection from the Rainbow Magic series out of curiosity, but won't give it any rating, since I'm undecided and not really the intended consumer. This series is in a close contest (for the greatest number of titles on the local library's shelves) with the apparently-similarly-conceived Beast Quest series. Its emphasis on marketing aside, it was better than I expected: not overly saccharine, the writing straight-forward, and the fairy-dusting kept within the requirements of the plot. I'm not so sure about the lesson implied (as another reviewer noted), whether the message is: "Be willing to accept assistance from someone bigger and stronger;" or "You girls need help from a male, even if he's just a frog." I would need to read further into the series to decide how that issue is settled, but I'm not sure that I'm curious enough to do that.
If my kids had gotten into fairies (instead of dinosaurs) when they were young I would have been OK with them reading this -- with parental guidance as far as sexist messaging, if needed.