If you believe the vaccination and a mask will protect you or your child from COVID-19 then you should where it.  Others should have the choice.  There is data that shows the vaccinated population carry higher viral loads and are transmitting the virus.  It is a matter of protecting yourself and your children the way you see fit.  If vaccinations and masks are effective then the vaccinated population having nothing to fear from the unvaccinated and unmasked.  There is a personal choice in this matter where each family assesses the risk versus benefit.  If you are allowing contact, less than 6 feet, sports, and spectators then shows you are not terribly concerned about COVID transmission.