The fact that 'The Goose Girl' is one of the lesser known tales by the Brothers Grimm makes this book all the more interesting (I doubt you could find many people who could tell you the basics of the story, unlike more well-known stories such as 'Sleeping Beauty', 'Snow White', 'Red Riding Hood' etc.). If you have read the original tale, however, this gives the story a deeper resonance, as you recognise certain characters who have been given a bigger role and more complexity.
Frankly, in the original story, the goose girl is a bit of a wimp, a real dumb blonde, but Hale gives her retiring nature a psychological background, so you sympathise with her instead of feeling irritated or uncaring about her fate. The relationship with the maid is particularly interesting, given that Ani believes this girl is her only friend. She feels like she's a failure as a princess, unable to live up to her mother's and other people's expectations: only her father and her horse Falada accept her as she is. But then her father dies, and Ani discovers that instead of inheriting the throne, she is to marry the prince of the neighbouring country, in order to avoid a war. Her mother gives her two gifts as she goes, in order to safeguard her, but she loses them, and so begins the real story of 'The Goose Girl', namely a girl finding herself and her feet in a strange country.
Ani's gradual development is realistic and interesting. Curdken's role and character are both expanded, and he becomes far more likeable in the process. The tragedy that happens to Falada is even more horrific in this story than it is in the original. The final three chapters of the story are really tense - even though you know things end happily ever after, you really do wonder how Hale will achieve this, and that is a mark of how good this book is. It's sad and scary sometimes, funny and sweet at others, and I'll certainly be reading it again.