From the Mixed-Up Files of Mrs. Basil E. Frankweiler Family Quotes
How we cite our quotes: (Chapter.Paragraph)
What happened was: they became a team, a family of two. There had been times before they ran away when they had acted like a team, but those were very different from feeling like a team. […] You might call it caring. You could even call it love. And it is very rarely, indeed, that it happens to two people at the same time—especially a brother and a sister who had always spent more time with activities than they had with each other. (3.58)
So what if they sometimes fight over things like how much money to spend? There's still an element of sweetness in Claudia and Jamie's relationship. And though neither of them would get so sentimental, they do become a "family of two."
As they once again reached the back stairs, Claudia asked Jamie, "With whom shall we dine today, Sir James?"
Jamie answered, "Oh, I don't know, dear Lady Claudia. Shall we find a good and proper group?"
"Yes, let us, Sir James." (4.80-82)
How fancy! In their own little elegant world of the museum, Claudia and Jamie get to live out her fantasy of being noble and rich. When Jamie plays along, it's not just because he likes it too—it's because she's his sister and he wants to humor her.
He must have thought STAY PUT exactly hard enough, for Claudia did just that. They never knew exactly why she did, but she did. (5.81)
You know those stories about how mothers and their children have weird, ESP based connections? In this story, it seems as though their sibling bond allows Claudia and Jamie to send messages to each other through pure brain waves. Which is good, 'cause their mom is probably too busy worrying about Kevin Brat.