I must admit. It's been a while since I have read the book but even then I had noticed that the movie was not following the book word for word. Yet, that is tipical of movies that are based on books, they are never exactly the same. One needs to remember that being based on a book is different then a visual reprodeuction of the book.
I was with my cousin and her friend ages 10 and 13. The both LOVED the movie and I enjoyed it so I gave it a 5 out of 5 because its a movie for kids and they should be the ones rating it.