Hermione's twin sister

"I have brought you two here to tell you something very important," Dumbledore said.
"You see Isabella, your last name is not Taylor. It is granger."
"You mean we're sisters," we said together.
"Yes but not just sisters twins. There is also more thing. You kids aren't muggle-born."

Most characters belong to the queen J.K. Rowling

The first few parts are done by It_is_me_ANA