I'm Snape's daughter?

The story of the daughter of Severus Snape, Elizabeth Eileen Snape. Her mother ran away, hiding from Snape when she found out she was pregnant. So he never knew that he became father to a little girl, a girl with pitch-black hair and the darkest eyes ever seen.
She grew up believing the stories her mom told her, that her father died during a car accident. And even worse.. To make sure Snape wouldn't find out, she raised her daughter between muggles trying to keep her as far away from the wizarding world as possible.
But her mother couldn't hide her forever, since she is a pureblood witch. It was only a matter of time before the letter from Hogwarts came flying in.

*This is a story based upon the Harry Potter books but slightly different, as an example. In this book Snape is 35, when his daughter is 11. So he was 24 when he had a relationship with 21-year old Raven Frost. So he's younger than in the harry potter books, also he's a lot better looking but everyone is still afraid of him.*