A relative of mine works in the public school system. A kindergarten age student had high fever, went to clinic and was given strep culture and standard influenza screen. No mention of cv19 test.
At this point are they looking at contact history, travel destinations, etc?
Without a lot more information about the child and the school, it would make sense to think more about Chicken Pox than Coronavirus.
If the Dad worked at Biogen, or the Boston Long Wharf Marriott...I wouldn’t be too worried.