Does Atticus follow the rule he gave Jack about answering a child's question when Scout asks him about rape?

Atticus does. Atticus had told Uncle Jack that he hoped his kids would ask him questions rather than finding out from the townspeople. When Scout questions Atticus about rape, he gives her a very "Atticus" kind of answer, "He sighed, and said rape was a carnal knowledge of a female by force and without consent." This, of course, is sufficient for a girl like Scout.