Harry Potter: The Hogwarts Valkyrie

[Strong female lead] [Villainess heroine] Audrey Travers, the daughter who had been missing from the Travers family for years, has finally been found! The fallen Travers family has at last found its heir. However, under the bloodline alliance of the 28 Sacred Families, Audrey will receive the protection of the family most closely related to her until she comes of age: the Malfoy family... Draco Malfoy discovers that his inexplicably acquired older sister is truly elegant yet vulgar, rational yet insane, kind yet cruel, and has a terrible temper... Audrey: Stay away if you’re a stranger. If you know me, get lost.