An example of a child photographer would be Jacques-Henri Lartigue. You can read an article on him and see some of his photographs:

http://www.masters-of-photography.com/L/la..._articles1.html .

I saw an photograph that he made when he was 11 (I think). His toy cars were placed on the floor of his room, and he photographed them along with a "gigantic" dresser and door in the background.