fast and dirty: their family has a lot of problems, namely the parents masking their abusive natures behind a pleasantville/stepford wives mentality. ryan did a lot of the raising of his two siblings, their brother died from an accident when ryan was 10 and watching him. their parents blame ryan to this day, and ryan cut ties with them when he was 16 - so the sister would’ve been relatively little still, maybe still ate up what the parents said. that’s the gist, i’m open to exploring and brainstorming more if you’re interested.