The story makes absolutely no sense for a whole multitude of reasons.
Firstly why on earth youd drive from London to Durham with your kids if you think you've got Corona, is beyond me. Also, leaving your kids to be looked after by older parents, especially those over 70, needs to only be done as an absolute last resort. Even ignoring fact it seems to be against the guidelines, it just seems like a daft thing to do.
All that said, I dont agree with not being able to go to my parents house, and I think that rule needs to be relaxed immediately. 10 weeks is far too long and it's not good for society. I no longer feel the risk is severe enough for such an extreme rule.