If you have to prove a point about the facts of life, might as well watch nature. Whether or not you'll be affected psychologically is a whole another story.
Given Kyouko's upbringing in what was strongly implied to be a family of devout Christian faith... I can actually believe her relative innocence on the subject of human reproduction. This isn't exactly something a church family would discuss with their children before they reach a certain age, after all, and Kyouko probably hadn't hit that magic number yet before... well, before.
They're copulating!!!They're copulating!*meow*kyaaah!Y-y-y-y-you can't see this!!!Huh? Why? It's a good thing if she gives birth to kitten!ding!I've got it!!!oh oh ohoh oh ohExtra explanation: even if Kyouko knows about animal copulation, she doesn't know anything about what goes inside what and what does it take to impregnate and make babies. When she was a child, she thought that "if two person kiss, they can have a baby", so now she has a vague perception of some particular movements that a male and a female must do together in order to have a baby.AH!Oh my, I wonder if it's all right to understand it like this......that's right...Even if, in human's case, I think that only a few people call it "copulation".Both humans and cats are mammals, aren't they!Doesn't this mean that humans copulate too!?