Andrina Cressida Black is a pureblooded witch; the youngest daughter to Cygnus III and Druella Black (née Rosier), and the youngest sister to Bellatrix, Andromeda, and Narcissa, respectively.
At Hogwarts School of Witchcraft and Wizardry, Andrina was sorted into Slytherin House; like all her sisters before her, and every member of her family at that point. An intelligent and highly gifted girl, Andrina particularly excelled in Transfiguration and Potions, but, received high marks in all of her classes. She attended Hogwarts in the years 1968-1975, graduating with a high number of NEWTS and as Head Girl of her year. She married fellow pureblood Ashwell Thornetwo years after leaving Hogwarts (1977) and gave birth to their baby girl, Casperin the Spring of 1980.