On at least a couple of records I have also seen son-in-law or step-son used as a term, with the child then described as "son of my daughter so and so". Apparently these terms used to have a more fluid meaning than they have for us today.

At that point I usually look at the parish records and try to make sense of it, put it on the back burner, or ask for help . . . not all of this is a straight forward as many of us would hope!

Good luck.