Hiya Copepod
That is a good idea.
However with kids, especially the young ones, they really don't show or feel hypo, no idea why but it happens. Some do and these are the lucky ones. Some of the younger ones will grow to be able to feel symptoms. Jessica never felt or showed anything until after we had tested and found she was hypo, it was only then that she used to go in and out of consciousness, never before, really weird. She never got to the point where she felt odd until it was too late and she was at collapsing point. She collapsed on another child during a spelling test at school one day, that was a shock for the other child.
A few times she would go white as a sheet but would be down in the 1's by then.
This is why testing really frequently is a must with these kids and when docs say only test 4 times a day, it really gets up my nose, they can't possibly know what is happening inbetween with lows and highs.