if the family was "suitably rich to tempt a [living] girl," the ghost marriage might profit them with the asset of having a daughter-in-law. since a daughter is not considered "a potential contributor to the lineage into which she is born," but rather "it is expected that she will give the children she bears and her adult labor to the family of her husband," the wife of a deceased son would benefit her husband's family by becoming a caregiver in their home.