Where to ... ?

Here's a little story ...
My sister is in the 6th grade, and recently she started school again. No more than a week passed and the kids in her class discovered a new way to play - throwing thistles at eachother.
Nothing unusual so far...
Yesterday my sister came home with a blood vesle broken in her eye (may not be the exact medical term). Apparently one twit threw some thistles at her, one got in her eye and the other three we managed to untangle from her hair. Naturally my mum got upset and called the form teacher and the twit's mother to ask them to calm down the young and restless kid. She didn't make fuss about it, she only emphasized that this kind of games could get dangerous.
Today when my sister got to school all of her classmates (they are all 12 years old) treated her bad and told her we overreacted.
What bothered me the most was not the fact that their formteacher didn't mention a thing about the incident or the fact that all thought we overreacted, it was the fact that one of the girs told my sister " Why did you tell on X - now all the boys will be upset and won't pay attention to us girls anymore ... "
You gotta be kiddin'me... I mean...she is only 12 and that is her majour concern right now ? What will she do at 18?
The kids these days took this to a whole different level...
Where to ?