Holy shit, that's heavy. Really, really heavy. The title is kind of misleading, since it seems she was an outcast for multiple reasons, but to even have that be a modicum of the reason for her committing suicide is completely unacceptable.
As far as the rate spike for prepubescent suicides, that is also a huge and perhaps more generalize-able phenomenon, with kids being thrust into the adult world and out of their own pockets of reality in a way that simply has never been possible in generations before.
Nah, even if it's only partially the bullying, it's the bullying. Simple "mental issues" for a child (to the extent that early childhood issues can be chiefly considered mental rather than environmental or behavioral), without some other sort of contributing factor, would not be expected to cause this.