Eyja is a servant you can hire for 150 in the quest Helping Hands. She was orphaned at a young age, and worked for Gunder, who "shared a bed with her" but never married after her. He never treated her badly, but never gave her much attention, acting like she was "just another part of his shop". When you hire her to work at Rosethorn Hall, she can provide Shepherd's Pie and Rosethorn Mead if you ask. She will also sleep in the basement of Rosethorn Hall, making her an easy target for vampires. If you are a higher level she seems to be quite skilled at hand-to-hand (this is not certain though).