When he keeps the curtains closed, it seems as if hardly any time has passed since they moved in; only in bright light he can make out the first grey hairs on Albus" head (it started earlier than with Harry, but Al is even less concerned about ageing than Scorpius or Avery). Or the still fine but perceptible lines on Avery's forehead (once he got into the habit of putting on an intellectual, brooding expression at every suitable opportunity, he hasn't been able to stop).