For 4-year-olds
By four, children start to understand that other people have their own feelings, and guilt becomes something they can actually sit with. That makes room for stories where the apology takes a little longer: a character hides what happened, feels uncomfortable, then owns up. Look for episodes where saying sorry is followed by doing something about it, helping to fix the mess or trying again more carefully. Four-year-olds also notice fairness sharply, so it helps when characters take their own share of the blame rather than all of it or none.