I just do not see any universe in which a twelve-year-old child with a gut wound dies quietly and peacefully. No seriously, she'd be a screaming mess, I don't care how fucking angelic she is. Unless she was lucky enough to pass out from the pain.

This just... ugh. I don't much care about the sex of a fridging victim, honestly. I find it annoying when ANY character is killed purely to advance the motives of a central protagonist. It's just lazy and bad all around, and disappointing to people who may identify with the "discarded" character more. Sure, it has more unfortunate implications when the victim is female, but it's a cheap and overused trick regardless.