While I would not necessarily consider this book "inappropriate" in terms of violence or sex, it does present a very unrealistic perception of relationships and a main character with endless complaining and insecurities, who relies on her new boyfriend for everything (and completely shuts down when he leaves her for a few months). If there is any feminist in you at all, you will probably dislike the book. The rest of the series only becomes worse in terms of appropriateness; however, you know the maturity level of your child better than I.