In that lively sense of the immediate which is the very air of a child's mind, the past became for her as indistinct as the future; she surrendered herself to the actual with a good faith that might have been touching to either parent. Crudely as they had calculated they were at first justified by the event; she was the little shuttlecock they could fiercely keep flying between them. The evil they had the gift of thinking or pretending to think of each other they poured into her gravely gazing soul as into a boundless receptacle. She was at the age for which all stories are true and all concepts are stories. The only thing done, however, took place when it was sighingly remarked that, either from extreme cunning or extreme stupidity, she appeared not to take things in.
The theory of her stupidity, eventually embraced by her parents, corresponded with a great date in her small still life; the complete vision, private but final, of the strange office she filled. She puzzled out with imperfect signs, but with a prodigious spirit, that she had been a center of hatred and a messenger of insult, and that everything was bad because she had been employed to make it so. Her parted lips locked themselves with the determination not to be employed any longer. And when, as a tribute to the successful application of her system, she was called a little idiot, she tasted a pleasure new and keen.

I encountered this passage while doing SAT prep material. I thought it was interesting.