I have no doubt she will feel ashamed when she gets older. Some of the ways in which I thought or didn't think when I was 12 are appalling now, too, because I can appreciate the subtleties in retrospect. Although she can't be held responsible for understanding what she did at an adult depth, it's an opportunity for her to be introduced to that understanding by those older who do get it - to start growing up. The lesson should sting.
Teaching her is her family's private business, though, IMO, because the mistake was between family. The extra publicity feels cynical. It's communal human nature to bond as a group over all being angry the same thing, and young generations have longtime been a safe and popular target for that. Stories about youths that at least seem to support the stereotypes of them that we love to hate are easy click bait.