How to talk to kids

I just came back from a wonderful trip at Colorado. I had the pleasure of visiting my brother's kids: Megan and Noah. Kymberly was visiting as well. I Love the little ones. While I was there we played in the rain, made up songs, played video/board games, and hunted for bunnies. One night I was up in Megan's room with the three kids (Megan, Noah and Kymmie). Kymmie and Noah was arguing about something. Megan said to me. "Auntie, since you don't have children. I'm going to teach you how to talk to kids." "You got to raise you voice a little." So in my parental voice I say: "Noah and Kymmie, behave."
"You have to say it with a little more anger auntie, and threaten to tell their Mommy and Daddy." So with my best parental voice I say, "Noah and Kymmie, stop it or I am telling you father and your mother."
"Very good and if they don't listen, you have to give them the count down!" Megan explain. "you're the parent now... you're the boss...you're in charge."
"NO laughing auntie."
I couldn't help it. She was very cute in her instruction.