I'm sort of thinking of a wunderkind/prodigy archer who was sort of the hope of the generation--a little bit older than the rest of the Kaidelings. Sort of a free-spirited big sister who built up a massive ego and maybe bullied her way through her time at the academy (which might be part of the reason why all of the others got bullied!). Only moments before her graduation (or maybe she graduated, depending on the timing), she was either victim of an assassination attempt or otherwise failed resulting in her vision being absolutely destroyed.

This broke her and she basically ran from home to waste away, only to return at the very end in a moment of love for her family.

The main kicker is that she'd come back a bit after the assassination attempt--her ability to shoot her bow and arrow would still be ruined and she has to work around that.