Abraham’s father called his daughter, Sarah, his daughter-in-law. She and Abraham had different mothers, but Terah was their father. So daughter-in-law actually gave reference to the children of the second family at that time. Today, because of laws enacted by the “lost children of the house of Israel”, we now use the term daughter-in-law to refer to our son’s wife. We also have mother-in-law, father-in-law, and son-in-law. All of these titles refer to members of the first family now. The “in-law” terminology helps to remind everyone that they are temporary members of the family and not permanent members. They can all be eliminated and replaced with the laws of divorce and remarriage. Do you refer to your daughter’s husband as son-in-law or is he your daughter’s husband? Big difference!