Introduction?

In this sixth book of the 'Wayward Children' series we meet a new girl and a new world; Regan hasn't been introduced in one of the previous books. It is expected that we learn more about her in the upcoming 8th book.

This book could have been a lot better. Regan learns at a young age that conforming to other girls will get her accepted as being normal. But she isn't 'normal', as she finds out at age 10, when she is not getting into puberty like the rest of her friends. Her so called 'best friend' shatters her trust by betraying her secret, so Regan is ready to find her door. Leading to the Hooflands, where equine-like creatures live. She is taken in by a herd of friendly centaurs where she befriends a young one.

For five years Regan manages to stretch out her 'destiny' to be a hero and save the world of the Hooflands. This big part of the story feels like not much is really happening. Also the conclusion of the story feels too abrupt; no indication of Regan's life after she finds the door to our world again.
I guess we should be patient for the rest of Regan's story.