Tonight with your 9 to 12 year old
The prompt
“What's a family joke that never stops being funny to you, no matter how many times we say it?”
What to listen for
If they immediately know the one and start laughing just talking about it, that inside joke is doing real work, it's a marker of belonging that's theirs, unique to this family, and worth keeping alive on purpose.
If they can't settle on just one, let them list a few, that's a sign humor is a real language of closeness in your house.
If they say "I don't know," bring one up yourself and watch their face; they'll usually correct you with the real favorite.
What this tells you
This shows you which piece of shared history has actually become part of their sense of belonging.