I have seen in several places that Hannah Deem was the daughter of Jacob, Adam's brother, and that Adam II was Adam's son. This made them 1st cousins when they married. I imagine this happened a bit with all the inter-marriages between the Deems and the Jenkins families--Emma Jenkins Cardey knows a lot more than I about that . . .
Relationships would be easy for court reporters etc., to mix up, and this happened a lot back then.