No one knows for 100% certain that she did it. Furthermore, it's a very unfortunate situation overall. If she did it, she did something very wrong. However, due to her age and circumstances, it's obvious that there was more going on. Teenage girls don't just randomly kill children. I hope the trial thoroughly investigates her background, family, mental health issues, and other problems she may have had. They need to consider the fact that she may be a victim, herself. No one likes to hear that, but it's true. Of course, all of this assuming she didn't take the blame for someone else.