Rosella knows that the Siren Maybelline was half human, half siren. So, her body would've been like when a normal human dies.
But the story did not tell what happened to the 'devil' who saved the Siren Maybelline. Nor where did he go with her body. It did not mention the small kingdom's name, either.
But when she was a child, she liked to have secret outings outside the palace, and she heard many rumors.
The Siren Elena was the sole daughter of Neptune, the king of the sea. So, Maybelline was the granddaughter. And so, the King sought after the 'devil' to take Maybelline's body, and repay him with eternal friendship to him and his descendants.
Another rumor is that the small kingdom was destroyed by a bigger kingdom, but no one knows what the kingdom was. But judging for the sea, the island, and the magic she feels around, she can tell that five hundred years ago, the Cullen Territory gained shape.
