Most young kids, especially elementary school age, have access to ATV equipment either in their garages or at their friends houses or through other community means. Its always best to teach them, even if you believe that they won’t gain access to this equipment. Better to be safe than sorry.
Having a conversation with your kids about ATV safety is the first step, especially the use of snug fitting helmet equipment. One of the next steps you could take would be to get involved with an organization like Mudd Safety, where they deliver ATV safety instruction to all ages of children and families and make sure your kids know the best safety practices for driving and riding on ATVs.