As far as I know, I'm descended from John and Polly as well. Their daughter, Narcissus, is my 3rd great grandma. I have a picture of her up on my Ancestry tree. I think there is some facial resemblance to the photo of her brother William Riley Potter that Elaine Watson uploaded to FindAGrave.
I've heard a lot about Native American ancestry in this line. Narcissus was called "Wassie" and it's rumored that her English wasn't perfect. Another note was that she raised her four grandsons after their mother became mentally ill (there is a bigger story that goes along with that).
How is everyone's research going?