Question: Who is the mother-in-law of Ecgwynn?
Sentence (from "Ecgwynn"): 890s), was the first consort of Edward the Elder, later King of the English (reigned 899–924), by whom she bore the future King Æthelstan (r. 924–939), and a daughter who married Sihtric Cáech, Norse king of Dublin, Ireland, and Northumbria.
Relevant evidence: Yes