Sarah Lupin-Black, daughter of Remus Lupin and Sirius Black, was 15 when she accidentally stumbled into a dinner with her dads friends, after being told to not come downstairs. That was also the day she became, the girl who was a secret. She hit it off with Hermione, Cedric's sister and the twins immediately, with one of the twins in particular. All character credits go to JK Rowling. Sarah Lupin-Black and Melissa Diggory are my characters though :)