[Edit]Elizabeth (who demands to be called by the more affectionate "Lizzie") is Ciel's cousin, the daughter of Ciel's father's sister, Francis, and her husband, Marquis Middleford. She's also his fiancee. Lizzie has known Ciel since childhood, and the two appear to have been very close. Despite this childhood connection, though, Ciel has not told her the circumstances of his parents' deaths and his own disappearance. Lizzie takes this in stride, not pestering him for information and continues to attempt to restore the close friendship.