The short answer: what to say to a child before a school interview is: very little, and nothing new. The car ride is climate control, not a cram session. Music, ordinary talk, and if you say one thing, make it this: "you already know every answer, because it's all about you." Every tip delivered in the car is subtracted from the calm your child walks in with, and calm is worth more than any tip ever offered at a red light.
The reframe that settles the whole drive: by the time you're in the car, preparation is over. The only variable still moving is temperature. Your child will walk in carrying whatever climate the car creates, and they're reading it from you: tone, pace, how your hands sit on the wheel. That makes the drive a job you can actually do well, because climate is fully in your control in a way answers never were. Aim the ride at ordinary. Ordinary is the gift.
What to say, then: ordinary things. The weekend, the dog, the song that's on. Their playlist is a legitimate strategy. Let them DJ. If the moment asks for one steadying sentence, use the one that's true: "you already know every answer, because it's all about you." It works because it's not advice. It's a fact that removes the exam from the morning. And then back to the song, because lingering on even a good line turns it into a briefing.
What not to say, and why each one costs. "Remember to make eye contact / speak up / sit straight". Tips at this hour are your nerves in a helpful costume, and each one hands your child a fresh thing to monitor in a moment that needed fewer. "This is really important": they know; stakes talk raises the temperature and adds nothing. "Your cousin loved his interview": comparisons install a benchmark on the doorstep. And the pop-quiz practice question at the stoplight is the single worst move available: it converts the car into the interview an hour early, with none of the interviewer's warm-up craft.
The logistics under the conversation matter more than the conversation, and they all take "try to," not "must": try to leave with enough margin that the drive never needs to hurry, try to feed everyone before you load the car, try to have the clothes question settled the night before. Every one of those buys calm at wholesale prices. A relaxed on-time arrival says this is a nice thing we're doing today more convincingly than any sentence you could compose, and it hands the threshold piece its best possible starting position; the goodbye at the door has its own page.
If nerves surface out loud, "I'm nervous" from the back seat, don't fix, and don't deny. Receive it: "makes sense. New people and new places are nerve-y. You'll be in the swing of it a few minutes in." That's acknowledgment plus forecast, and it's complete; resisting the urge to append three tips is the whole skill. Then the radio again. The drive home is a different piece with different rules, but the drive there has only one rule, and you now know it: arrive ordinary.
Jennifer Hines spent twenty years as a Dean of Admission at Noble and Greenough School. Her free guide, What They're Really Asking, decodes fifteen interview questions from the other side of the table, and shows why the quiet kid is often the one who lands them best.