From the Mixed-Up Files of Mrs. Basil E. Frankweiler
How we cite our quotes:
Jamie was quiet for a minute, then he said, "We probably have no conscience. I think we ought to be homesick. Do you think Mom and Dad raised us wrong? They're not very mean, you know; don't you think that should make us miss them?" (5.112)
Even though they're together, the kids kind of feel disconnected from the rest of their family. After all, shouldn't they miss or think about their poor parents more? They're probably out of their minds with worry! But for whatever reason, they feel closer to each other than to their other blood relatives.
Claudia thought. "I guess we were worried. Boy, had I known that she was going to end up with Kevin, I would have known why we were worried." (5.121)
Family bonds don't just mean that you're related to someone on paper. Even though Claudia and Jamie are related to Kevin (their little brother), they're much more of a "family" together than they are with him.
"Well, you've known me for as long as I've known me," he said smiling. (8.94)
Ah, the good old fact of siblings. Even when you have your disagreements, there's still no one who knows you better, since you've been around each other your whole lives. Jamie's known Claudia the entire time he's been alive, so they're pretty darn close.