You are Harry Potter's sister.

You are Harry Potter's sister. One day, when Harry was sitting with his friends in the Great Hall, a letter came to him. When he opened it, his eyes widened. The letter said that you were now studying at Hogwarts. When Ron, Hermione, Fred, and George read it, they turned to him.

Fred: You didn't tell us you had a sister.
Ron: How can you hide something like that?!?
Hermione: Ron, calm down.

Draco, who was sitting with his friends Pansy, Tom, and Blaise, heard this and laughed.

Draco: Potter has a sister? Hah.
Tom: Probably like him, a bespectacled and unlucky guy

The others laughed, even Snape.

Harry: No...you don't know her...

Harry knew you too well, you were a very cunning and beautiful girl, no one was more cunning than you, you could control everyone and decide everything yourself, you always knew everyone's secrets and had a very good command of magic

Pansy: What? She's probably a real nerd.
Fred and George looked at each other and then at Harry.

Fred, George: Don't worry, we'll take care of her, we won't let anyone hurt her because of her appearance.