Once upon a time

We recently moved Margot's crib into Portia's room, and have started putting them to bed at the same time. (In the past, we've been putting Portia to bed, then rocking Margot in the chair until she fell asleep. We are now letting her put herself to sleep.)
As I'm putting the girls down for bed, I have started telling them stories. They are short, and completely made up, and all about them. Portia calls them "Portia-and-Margot stories." She loves them, and makes me tell like 8 in a row.
What's that? You want me to tell you one?
Done and done.

Once upon a time, there were 2 little girls named Portia and Margot, and they were sisters. One night, as they were going to bed, they heard a tap on their bedroom window. Portia opened it, and saw that the stars had come down out of the sky and were waiting outside for them.
The stars said "Hello girls, we need your help! The moon is very sad and won't come out into the sky!" So Portia and Margot jumped onto the stars and flew up into the sky to the moon's house. They knocked on the door, and the moon answered. It was crying!
Portia and Margot said "Why are you crying?" The moon said that he was sad because he thought no one liked him. But Portia and Margot told the moon that they loved looking at him every night! So the moon was happy again, and he jumped up into the sky!
Portia and Margot climbed back onto the stars and flew back down to their room, and went to sleep, dreaming of the moon.
The End.