If your child is vaccinated - there is a lower chance she gets COVID-19 - the disease. And if she does get it - it will be milder. But she may not get it at all

If your child is vaccinated - there is a lower chance she gets COVID-19 - the disease. And if she does get it - it will be milder. But she may not get it at all with the vaccine just because the immune system is trained to eliminate it upon entry. In the assumption that vaccine does not have any side effects, the strategy to vaccinate is strictly dominating in game theoretic sense. Let alone the fact that she has much lesser chance of being the spreader.