We have kept our four year old daughter home from school since March, despite it being open. Today, two staff members are going for Covid tests. Either way, I am happy we have decided to still keep her home.
You are a good parent. Every parent should be making informed decisions on how to best protect their family. Until kids get to be about 9 or ten, they aren't going to understand things like social distancing, wearing a mask, not touching their face, etc.