In trying to resolve the issue of the Martha Cox married to William (Ricmond) Terrell, I came across this on Wikipedia, which states:
Richmond Terrell
Richmond Terrell was born in Reading, England in 1624. After his father and grandfather, he was among the third generation of descendants to use the current spelling of the surname. He emigrated to the United States in 1656 and settled in New Kent County, Virginia. His brother William Terrell (born 1629) appears to have arrived in America sometime between 1658 and 1665. It is not known whether his brother stayed in the U.S. or returned to London. Richmond had several children including a son also named William. It has been speculated that this William is the same William Terrell that later married Susannah Waters, but due to a lack of documentary evidence, this has not been proven to the satisfaction of many historians.[1][3]
William Terrell who married Susannah Waters
This William Terrell was born around 1659 and died around 1743.[1] He married Susannah Waters and is a direct ancestor to several notable Terrells in the United States as well as other Terrell descendants including Jimmy Carter and Barack Obama.[3] Among historians, there is a lack of consensus regarding which of the early Terrells in America he is directly descended. One theory is that he is the son of the immigrant ancestor Richmond Terrell, but he may also be descended from Richmond's brother William. Gary Boyd Roberts in his authoritative volume, Ancestors of American Presidents, covers only nine generations of Carter's ancestry (going back to Joel Terrell, William's son) and ten generations for Obama (going back to Hannah Lewis, William's granddaughter), so the issue is not addressed in their respective ahnentafel charts.[3] In Reitwiesner's ancestry chart of Obama, despite covering sixteen generations, it does not list any ancestors for William Terrell.[4]
https://en.wikipedia.org/wiki/Terrell_(surname)#William_Terrell_who...
I had thought Richard Terrell was the father of William Terrell who married Susannah Waters (one publications shows her maiden name as Walters rather than Waters). Notice it also doesn't refer to that William as William Richmond Terrell as listed here on Geni.
In any case, it is saying that William who married Susannah is NOT a proven son of the parents attached to him here on Geni.