The parent who stays calm in public may need support in the car afterward.

Composure in front of other people costs something, and the bill arrives later. A parent handling a hard moment in a shop with a level voice has spent whatever they had, and the shaking usually starts once the doors close and nobody is watching. What looked like ease was effort held together for an audience.

If you were there, say something afterward rather than praising the performance. A message that says today looked hard, and you did well, reaches further than admiration. If you are the one who held it together, let someone know you are wrung out, and let the recovery take the rest of the evening.