ummmm,
Most of us went to school "at a very young age" - me too! It was "approved" in those days.
sophie,
There you go with that crystal ball of yours again? Give me one good reason why the child's home should not be the first port of call? You might embarrass the hell out of someone who, for all you know, because you haven't bothered asking, may have a perfectly legit reason for the situation with the child?
Besides, the jurisdiction of the school does not encompass its journey there and back, therefore why should a school take precedence over a parent? What if, for example, someone saw fit to call the Police because they saw a 5 year old walking alone? The first thing the Police would do would be to take the child home to find out why it was out alone, not to its school.