Two Little Girls

Chloe and Cassidy have started this fun new third person game. When they tell me something that happened, they talk about 2 little girls, who's names are Cassie and Chloe.

Examples:
Cassie said to me yesterday, "Mommy, somebody cleaned up their toys." I said, "who?" She said, "a little girl, and guess what her name is....Cassidy!"

A few days ago, Chloe turned to Brian and said, "Mommy doesn't want me to watch a movie. But there are two little girls, and their names are Cassidy and Chloe, and they REALLY want to watch a movie. PLEASE!!!!"

Whenever they have done something they know is wrong, and I ask who did it, they say, "a little girl." When I close and lock my door (they hate it when I lock my door), I hear knocking, and "somebody's knocking on your door Mommy, come see what's their name." (yes, they say "what's their name.")

Should I use this to my advantage to teach them? It is quite funny to hear, and they get the cutest looks on their faces when they say these things too.