You and your family bubble gave to self-isolate as it's then too late to be tested, this is how I am interpreting the gov.org instructions.
No one in household has symptoms, yet, I am just investing for (probable) future reference.
So this means for every kid temperature this season we are all off to the testing centre? Well I mean it could be a daily outing because it's unlikely we all fall together, you know how bugs work, they move around the family person to person.