This is a wonderful book, appropriate for all ages. I would recommend it and the two sequels written.
I really wish someone had edited this manuscript, because it has a lot of potential. It is as well imagined as the Eragon series, and look where that has gone. As to the objections about the main character, I believe her actions are meant to be humorous. She is not nicknamed "Der" for nothing. Think of her as the Homer Simpson of the fantasy world.