Aunt Em is the guardian of Dorothy Gale and the wife of Dorothy's Uncle Henry. She wad once a beautiful woman, but a life of farming rendered her grey and older than her years.
She and her family lived on a farm in Kansas, until the farm faced foreclosure. Shortly thereafter, she and her husband took up permanent residence in Oz, where she was appointed Royal Mender of the Stockings of the Ruler of Oz, preferring for herself a simple life to one of royal luxury.