I have always done my own kids illnesses as a give the parent a heads up and choice of coming or not. If they come they pay and if they don't they pay half fee because I was still open. It is up to the parent to assess the risk to their child. At the same time they are reminded if their child catches whatever they will be forced to stay home. Normally they send them because they feel they were already exposed to what my kids have and it is just a matter of time so better to try and get a day of work in while child seems ok still since they assume they will be off later in the week.