My rating: 3, 5 sparkling stars.
This book is listed for children between 9-12 y.o.
I didn't read the previous books, so I was a little lost at the beginning thinking the Unicorn! was some kind of imaginary friend. But it happens to be her best friend/companion. I'm sure you are wondering: a Unicorn! Well, like the NoticeMeNot (HP) and the Mist (Percy Jackson) , they have...tatatán... the 'Shield of Boringness'
Those scary things like starting a new friendship, summer camp, a new school term, adults believing or not in her, and even help your 'frenemy'-- tour the pages... and little lessons.