I don't know if I could pick a sentence, but this one gave me chuckle.

In Chapter 21, Elinor and Marianne meet the Miss Steeles. They are doting on the children. "Sweet little Annamaria" gets scratched by Lady Middleton's pin and starts wailing. They all do everything to make the child stop crying. But Jane Austen observes, "With such a reward for her tears, the child was too wise to cease crying."

So true! I've seen it happen so many times in my own interaction with parents and children.