Hi Ted and everybody, In their every day conversation when referring to a relative our ancestors (just as we do today) would have described the relationship e.g. "the wife's brother" or "my sister's son." The difference being that whereas we know the formal terminology used to define each of our relations in many cases our ancestor's did not know nor in fact did they need to know. Most working class people rarely had cause to write and often signed their own name with a cross so the only time they had to go through the inconvenience of coming up with unfamiliar words would be every ten years for the census. I have found that stepchildren were often entered on the census as son-in-law or daughter-in-law. It is easy to understand the heads of household's reasoning. After all if the wife's brother was the brother-in-law and the wife's father was father in-law then surely the wife's son was son-in-law. In my own tree I have a genuine daughter-in-law simply listed as "son's wife" and the grandchildren listed as "son's daughter" or "son's son." In another extended family the son's children are listed correctly as grandson/granddaughter but in the same large household the daughter's children have been listed as nephew or niece. Best wishes, Chris