auDNA testing between Jay Lynn Stills and Maynard Ivan Stills suggests a second cousin relationship. However Y-DNA testing does not match suggesting that William is not the ancestor of Maynard and thus not the father of Smith Alexander Stills. However, that leaves the possiblity that Nancy Tarton is the mother.
The paper evidence suggests that Uriah Ricker is the father of Smith but DNA testing is needed to confirm.
Sheila Tarlton Ellison, desendant of Susan Jane Tarlton suggested that the correct the spelling of Nancy's middle name. According to her daughter Susan Rilla Jane Stills Wills Ricker, the spelling was Mariah. Information provided to Michael Lee Stills in 2009 on Ancestry.com.
It may be possible to confirm family relationships with Nancy by comparing test results with other carriers of her mitochondrial DNA.
However, there are no known mtDNA test-takers in her direct maternal line.
It is likely that these autosomal DNA test-takers will share DNA with Nancy: