@seawall If you're okay with anti-advice ... don't introduce the concept of bills too early. Like, say, before mid-teenage years when the concept of recurring bills starts to be applicable.
Speaking from experience: I was parentalized waaaay too early, and "helping with the bills" was one of those adulting things. I ended up maybe a little more financially responsible, but at the cost of having real trouble spending "fun" money on myself and my family, decades later. (Yay, therapy?)