Yes, I am a decendent of Madison Hemmings. However, I derive from their child Sarah Hemings. Meaning that my family and I do not have jurisdiction over testing William Hemmings. Anyways, our lineage cannot be proven through DNA testing since there is no direct line of male descendants from Madison Hemings as there is for the descendants of Eston. But 200 years of stories passed down from generation to generation is enough prof for me. I am sorry that you are so skeptical about the subject.