Help your child write five questions for someone in the family — a parent, a grandparent, an aunt — about their childhood.
They conduct the interview and write down or record the answers. Your only job is to stay out of it.
Afterwards, ask what surprised them most. That question turns a list of answers into something they actually thought about.
Preparing questions in advance, listening well enough to record an answer, and then reflecting on what was surprising is the full arc of an interview. Hearing that an adult was once a child who got things wrong reliably shifts how a child sees them.