Sarella Sand (Alleras)

Fourth of the Sand Snakes, daughter of a trader-captain of the Summer Isles, and the one Oberyn's other daughters speak of only when they are sure no one is listening. She had her father's mind for books and the maesters' arts, and when he died she was already gone from Dorne. By A Feast for Crows a slim, smiling, ebony-skinned novice called Alleras has appeared at the Citadel in Oldtown wearing a man's grey robe and shooting the targets in the yard with the longbow of a Summer Islander; the other novices have nicknamed him the Sphinx for the riddle he is, and not one of them suspects that the sphinx is a girl, and Oberyn Martell's.