Governor William Stone of Maryland, in his will written 3 December 1659, named his brother-in-law Francis Doughty and his brother Mathew as overseers and guardians to his minor children. Governor William Stone was married to Verlinda. Francis Doughty's first wife was Bridget and his second wife was Ann Graves, widow of William Cotton and Nathaniel Eaton. William Cotton [then married to Ann Graves] named in his will "Brethrin-in-Lawe Capt. [later governor] William Stone and Captain William Roper" as overseers. William Roper was married to Katherine.
The language in both wills is consistent with the explanation that Ann Graves, Verlinda, and Katherine were sisters, daughters of Thomas Graves and his wife Katherine. Thus, Francis Doughty was brother-in-law to William Stone because they were married to sisters Ann and Verlinda Graves. William Stone and William Roper were brothers-in-law to William Cotton because they were married to Katherine and Verlinda Graves, sisters of William Cotton's wife Ann Graves. Further, both William Roper and his wife Katherine and William Cotton and his wife Ann Graves had daughters named Verlinda.
Some authors initially suggested that Bridget, the first wife of Francis Doughty, was a sister of Governor William Stone of Maryland because William Stone named Francis Doughty as his brother-in-law. However, that relationship does not explain the language in William Cotton's will.