Half Blood Royalty

We all know the story when it comes to Harry Potter. The baby who defeated You-Know-Who, losing his parents in the process. Everyone in The Wizarding World know about him. He's famous. The chosen one. What those people don't know is that Harry Potter wasn't the only child in the room that night. Another child, another bloodline. Just one year younger than Harry was another baby. A girl. Fathered by one most wouldn't have expected to pair with Lily Evans-Potter.
Melody Snape was the daughter of Severus Snape and Lily Evans. Slytherin student of Hogwarts. Lover of Potions class. Overprotected by both her father and her older half-brother. And most importantly, loved by the one boy of the family her father and brother both mutually disapprove of.
Torn between the good and the bad, Melody has to decide which path of direction would point her life in the correct direction. Will she choose to stick by her father's side, as he always intended; Or will she choose to follow the path of her older brother, once again fading in the background as he takes charge; Or will she choose the path paved for her, joining forces her father spent fifteen years fighting against for the safety of his own daughter?

Disclaimer: The world of Harry Potter and all of its characters belong to JKR and Warner Brothers
Disclaimer pt. 2: This world doesn't match what happens in the Harry Potter series - I've taken these characters and created my own little version based off their world.