if the kid has been educated in the handling.
As has been pointed out several times, it isn't illegal for a child to carry or to use a knife as long as it is a legal knife for the situation and the situation is appropriate for knife carry/use. Supervision and education is the point. A child needs supervision to buy a knife and education on how to use it. The point of the current legislation is to ensure (or more likely to improve the chance) that an adult is involved in the whole knife buying/using process.