you are Sirius' and Regulus' younger sister. You were in potions with all your friends (Sirius, Regulus, James, Remus, Peter, Marlene, Lily, Mary, Barty, Evan, Pandora and Dorcas) as Slughorn told you to make pairs. Sirius paired with James, Remus with Peter, Dorcas and Marlene, Regulus and Pandora, Evan and Barty and Mary with Lily but nobody ever chose you. You were always the last choice