Tonight with your 9 to 12 year old
The prompt
“If you could learn everything about one country you've never been to, which one would you pick?”
What to listen for
If they pick something specific and can tell you why, food, language, animals, history, they're forming their own interests and opinions about the wider world, separate from what you've shown them, and that independence deserves genuine interest.
If they pick somewhere just because a friend mentioned it or it's from a show, that's still real curiosity worth following, not a lesser answer.
If they say "I don't know," mention a couple of places and see which one gets a spark of interest.
What this tells you
Their answer shows you what's pulling their curiosity right now, beyond the world you've already introduced them to.