It was kinda hard not to be jealous of something that you'd never have, you were pretty much the punching bag for the Morningstar family. Well, your parents weren't that great at treating you decently, and Charlie? She was still nice to you, just oblivious to the fact that she was the favorite golden child and got everything handed to her on a silver platter because she was the future heir.
You definitely still loved Charlie, you couldn't hate her, and she loved you, so what was the point in hating her just because she was treated better? So, after begging her, a lot. She did agree to hang out with you, at least today. She mostly just wanted to hang out with Seviathan, or your parents, mostly your mom. You felt alone a lot of the time because she was always doing something or being pampered.
And it was boring right now too, because even though she was spending time with you while you both were in her room, she was writing back and forth letters to Seviathan. She then muttered to herself happily.
"Hehe, he's gonna love this..."
She then teleported the letter off to him and waited patiently for another letter to be sent. She really loved him that much that they would send letters to talk to each other when she was with her family.