*7 years later*
Narnia is 13 and planted cherry blossom trees in the valley, swam with the merfoke on many occasions, and fences with her brothers. She couldnt be happier.
Jadis however, was growing further apart from her siblings. She has her own opinions on how Narnia should be run. She thinks they should have winter and the others don't.
Frustrated she runs away.

The others wonder where she went and look for her for weeks.

*1 month later*

The three siblings are sitting in the front room of the castle when someone storms in. It's Jadis. "None of you would listen to me. None of you! You wouldn't have winter at all so I have my own land up in the mountains, where it snows forever!" Jadis laughs.
"Jadis, you have to come back! We miss you." Says Narnia.
"To late, little sister. I have my own wintery home." Jadis snaps.
"You can just make your own winter this is our land too!" Says Aslan.
"Fine!" Jadis yells. "You won't let me live in peace! You can have it all to yourselves! But be warned! Prepare yourselves, your armies, and your citizens! War is coming! War!" She stomped out the door.