Who is Eliduc's Wife from The Lais of Marie de France and what is their importance?

Eliduce's is a noble knight who leaves his wife behind to become a mercenary in another kingdom, where he falls in love with a fair maiden. Eliduc tries to bring his mistress home with him, but his wife discovers her. Eliduc's wife allows him to stay with his mistress while she becomes a nun. Eventually, his mistress also becomes a nun and Eliduc himself joins the church.