Granny Weatherwax's lacking knowledge of how to treat children:
She was never quite certain about children, thinking of them — when she thought about them at all — as coming somewhere between animals and people. She understood babies. You put milk in one end and kept the other as clean as possible. Adults were even easier, because they did the feeding and cleaning themselves. But in between was a world of experience that she had never really inquired about. As far as she was aware, you just tried to stop them catching anything fatal and hoped that it would all turn out all right.