The subject matter was a good one, and like others have stated, the intentions for the book were great, but I agree that even though the story was written well, it missed the mark in areas too.
First, most kids would be saddened to leave where they have grown up especially if they had friends, a social life, etc., but in her case, she really didn't have much of a life. She went to school and home. She had no friends, and didn't even socialize with neighbors until too late. Moving to New York should have been exciting for her...a chance to start fresh. For someone like her, I could imagine it was also a little scary, but she just didn't come across as a typical teenager. For example, she liked the pizza delivery boy in Ohio, but then she doesn't like any other boy she meets including Alex. She is 15. What 15 year old girl isn't thinking about boys. And I agree with what someone else said, I also began to think that Alex was gay until nearly the end of the book. I thought that he was so amused by her and only wanted to be her friend because he wasn't interested in the fairer sex. Talk about misleading. No teenager is not hormonal...
Second, although bullying is extremely serious, it didn't read as desperate as I would have expected. Yes, it was mentioned that there was name calling, and there was the scene where she was in the bathroom then the beating. Those were definitely serious issues, but it just didn't come across as bullying until that beating. The bathroom scene was bad, but I also thought she could have stood up for herself and it was more a case of jealousy. Even the friends didn't get involved in the actual harrassment. Julia was extremely meek. Which is why it is surprising that she would take a stand against bullying in so public a way to to try to pass a law. And yes, it is hard to believe that she managed to get a new law passed. Things just are not that easy.
Was it a bad story, no. But, it also wasn't 100% believable either. A girl who is from a well to do family may accomplish getting in front of a congressman, but you also would not expect bullying for someone in the upper middle class unless the person was extremely introverted, geeky, etc.