Evans?

Everyone knows the Evans.

Petunia, despite her sisters she's the Valedictorian, honors society, the perfect private school daughter.

Lily, their parents pride and joy, the perfect witch, teachers pet, the dream daughter.
But everyone forgets there's one more.

Lavender, Lily's twin, also a muggle-born witch, who's always been hidden in the shadows of her sister, not wanting to overbear Petunia at home and Lily at school, so she hides in the shadows

6th year, lord only knows what can happen.