I took my daughter to the zoo this week. Before we left, we stopped by the gift shop to pick up a souvenir. I let my daughter give the woman at the cash register the money and after we were finished my daughter said to her, “Have a nice day!” It was very cute.
As we walked toward the door to leave, my daughter turned back to the woman and said, “You forgot to say that.”
I turned to the cashier while I was laughing and said, “You just got busted for customer service. By a 5-year-old!”
My daughter totally rocks! 
Your daughter (whose name shall remain annonymous), could be a secret shopper now. That’d be fun!