http://en.wikipedia.org/wiki/Ealhswith

Ealhswith of the Gaini was born c. 852 in Mercia. Her name means "Temple strength".
Her father was Æthelred Mucil, Ealdorman of the Gaini. She was married in 868, to Alfred the Great, king of Wessex. The children of Alfred and Ealhswith included Edward the Elder, later king of Wessex, Ælfthryth, who married Baldwin II, Count of Flanders, and Ethelfleda, who ruled as Lady of the Mercians.
After Alfred's death in 899, Ealhswith became a nun. She died on 5 December 905, and is buried in St. Mary's Abbey, Winchester, Hampshire.
Also ref. History of the Anglo-Saxons by Sir Francis Palgrave for more details on her husband Alfred the Great.