I don't think it's panicking to test. After all the symptoms might be milder in children but they could pass it on to other more vulnerable members of the family or wider community. This seems quite an unpredictable illness so I do feel it's important to be as careful as we can whilst trying to make sure life goes on.
Legal ban on smartphones, schools in England
My dd was following guidelines as given by the NHS. Given that her little one was hospitalised, including a blue-light emergency, three times last year for respiratory problems, a test seemed eminently sensible. Not only that, but her other GM has had an organ transplant so it’s pretty important for them to know and be prepared.