The children do most chores around the house because it’s just part of family life. Ethan has are some optional chores, rather like extra credit, that he can choose to do in exchange for money for spending on frivolities that I’m not willing to buy him. While the value of that money (or its absence) seems important to him as we pass the candy isle, it doesn’t rise to the same level on the job site.
Eliana has a contagious willing spirit. Any attempt she makes at a task instantly motivates her big brother. When I offered her Ethan’s job of moving rocks onto the the berm that had spilled past its border, Ethan had a sudden inspiration, and I had two willing workers.