Tonight with your 9 to 12 year old
The prompt
“Do you think it's fair how we split up who pays for what in this family? What would you change?”
What to listen for
If they have real opinions, about allowance covering certain things, or who pays for outings, that's them practicing fairness and money-sense at the same time, which is worth engaging with seriously rather than dismissing as kids not understanding money. Notice if their proposal is self-serving or actually thoughtful about the whole family; both are developmentally normal, but the thoughtful version is worth praising specifically.
If they say they've never really thought about it, that's an opening to explain a little about how the family handles money, in age-appropriate terms, which builds trust and understanding over time.
If frustration comes up about a specific unfair-feeling moment, let them fully explain it before you weigh in.
What this tells you
This tells you how they're starting to understand fairness and responsibility around money, and how much say they feel they currently have in family decisions.