Eadwyn is an Anglo-Saxon feminine name composed of ead (wealth) and wyn (joy).
Edwyn [Sharon Turner 1805 The History of the Anglo-Saxons, 1st edition, 4: 129].
Eádwyn [John Kemble 1849 The Saxons in England, 1st edition, 1: 506].
Eadwynn [William Searle 1897 Onomasticon Anglo-Saxonicum, page 194].
Eadwyn [Dorothy Whitelock 1930 Anglo-Saxon Wills, page 15].
Ēadwynn [Patrick Hanks & Flavia Hodges 1988 A Dictionary of Surnames, page 162].
Éadƿynn [Oswin Kinsey 2016 English Compound Names, 2nd edition, page 115].
wealth = Ead- [Henry Bradley 1888 The Goths, page 369].
Wyn = Joy, pleasure, delight [Joseph Bosworth 1838 A Dictionary of the Anglo-Saxon Language, 1st edition, page 486].
A woman named Eadwyn was bequeathed by the Will of Wynflæd: “and Cynestán, and Wynsige, and Bryhtríces sunu, and Eádwynne, and Buneles sunu, and Ælfweres dóhtor” [John Kemble 1848 Codex Diplomaticus Aevi Saxonici 6: 133 (number 1290)]: “Cynestan and Wynsige and Brihtric’s son and Eadwyn and Bunele’s son and Ælfhere’s daughter” [Dorothy Whitelock 1930 Anglo-Saxon Wills, page 15].