THE GAMER NEXT DOOR

Answer: Yes. J.K. Rowling was going to give Hermione a younger sister who was a muggle. However, by the time "Harry Potter and the Order of the Phoenix" came out, she felt that it was too late.

Chosen answer: No, he doesn't. He says Percy's name in the second book "Harry Potter and the Chamber of Secrets", when they are on the train ride home.