The youngest daughter of Jack Mercy, Willa is a 24 year old young woman, raised on Mercy Ranch, Willa has spent her life trying to make her father proud of her. Willa's mother died when Willa was still a baby, making it impossible for Jack Mercy to send Willa away as he had with her two older sisters and their mothers. Willa was ignored for the most part by her father, and raised by the housekeeper, Bess Pringle.