She is a key tragic figure around which the story hinges.  A Saxon needlewoman recruited to work on the BT, she is the victim of Odo’s persistent sexually predatory behavior.  In real life, there is a mysterious figure “Aelfgyva” and “a cleric” in the Bayeux Tapestry that no one has been able to understand.  So I invented the backstory with Aelfgyva and Odo.