I was sewing in the basement while Addison and a friend were playing. 

They had divided up all the play money and were buying toys.  The friend ran out of money and wanted to start buying things with a credit card.

"You can't do that because a credit card is the same as cash.  You have to have money to pay your credit card or you can't use your credit card."

When the friend suggested that she could pay money later . . .

"No, you have to pay it at the end of every month, not just wait until you get more money because you might never get more money to pay your credit card."

I was proud. 

I know she's at a complete disadvantage in this game, but if she'll remember this principle, she'll be at a complete advantage in life.