Shot is handled by defender in the penalty area and goes in the goal. What punishment for the defender?

At training this evening, a sequence of events occurred that led me to question what I would do in a match. I coach the U12 team and sometimes ref their games when we have a friendly match.

Green team player had a long range shot from outside the box. Pink team defender was standing in the penalty area and had their arm raised and the ball brushed their hand and then carried on into the goal.

Green team celebrated the goal. Pink team tried to claim they had handballed it and so the goal shouldn’t stand, but obviously they would then have had a penalty against them.

My understanding is that the goal stands as I would have played the advantage for the green team, after the ball struck the defender. But would the pink defender receive any sanctions for the handball, as a foul isn’t then given?