aka Aelftryth. Slew her stepson Edward (Eadward) (The concise dictionary of national biography. Psrt 1 : from the beginings till 1900. London : Oxford University Press, 1969, pg. 9). Became a nun in 986 (Directory of royal genealogical datas - WWW site). This site states her husband was , Ethelwald of East Anglia, Ealdorman of East Anglia. Interred Wherwell Abbey, Hampshire. McBride web site concurs her husband was Edgar.
Ælfthryth was the daughter of Ealdorman Ordgar. Her mother was a member of the royal family of Wessex. The family's power lay in the west of Wessex. Ordgar was buried in Exeter and his son Ordwulf founded, or refounded, Tavistock Abbey.
Ælfthryth was first married to Æthelwald, son of Æthelstan Half-King as recorded by Byrhtferth of Ramsey in his Life of Saint Oswald of Worcester. Later accounts, such as that preserved by William of Malmesbury, add vivid detail of unknown reliability.
According to William, the beauty of Ordgar's daughter Ælfthryth was reported to King Edgar. Edgar, looking for a Queen, sent Æthewald to see Ælfthryth, ordering him "to offer her marriage [to Edgar] if her beauty were really equal to report." When she turned out to be just as beautiful as was said, Æthelwald married her himself and reported back to Edgar that she was quite unsuitable. Edgar was eventually told of this, and decided to repay Æthelwald's betrayal in like manner. He said that he would visit the poor woman, which alarmed Æthelwald. He asked Ælfthryth to make herself as unattractive as possible for the king's visit, but she did the opposite. Edgar, quite besotted with her, killed Æthelwald during a hunt.
The historical record does not record the year of Æthelwald's death, let alone its manner. No children of Æthelwald and Ælfthryth are known (wikipedia.com)