As you said, the movie is rated PG 13 which means it should be appropriate for most children age 13 and up.  However, the PG is important. That means that parents need to decide if they think the content is appropriate for their child. You can view a brief excerpt online to help you make your decision or sounds like you may have read the book. Think about how your child reacts to other violent media images. Even some children over 13 might be disturbed by some of the content.  And, seeing a movie can be quite a different experience than reading a book.
You should also think about what it would mean to your child to not be allowed to see the movie.  If that's your decision, try to make sure that your child doesn't experience this as a punishment.
The fact that you are asking this question says a lot about how seriously you take your responsibilities as a parent.  Good for you!

Jeanne H. Brockmyer, Ph. D. education.com expert clinical psychologist