Guy, It's been 9 years since you sent your message. Hope you're still around.
First of all, Temperance was never a Butterworth. She and her husband William Calvert knew John Butterworth in York Co., but John was not her father.
John Butterworth was an English sailor who settled in Accomack Co., VA in 1725 and remained there for several years. During that time he sued and was sued by a number of Accomack citizens. Some of the lawsuits involved fathering illegitimate children.
One of the families in Accomack that befriended him were the Gibbons. Around 1728 Butterworth moved to York Co and opened an ordinary (tavern). The Gibbons family paid the surety so he could open it.
Before Temperance married William Calvert in York Co., she was married to Thomas Robins. Robbins owned land on Chincoteague Island in Accomack Co. Thomas Robins also had a wife who died. Temperance was his second wife in York Co.
The maiden name of Temperance is unknown.
The following information may be only a coincidence, or it may help in establishing William Calvert's ancestors.
Christopher Calvert of England moved to Accomack Co., VA in 1636. He and his wife Elinor had one daughter Mary, and four sons Christopher, Jr., Charles, John, and George. The children were born between 1652 and 1665. There are no records showing if the four sons married or not. Christopher Calvert died in 1682. His apprenticed his son George to be a shipbuilder in 1680.He had another son, John, who was a carpenter. His eldest son, Christopher Jr., was a tobacco planter. Charles is believed to have operated a tavern for Middleton family in Accomack.
If any of Christopher's sons married, they may be the father of William Calvert of York and Chesterfield counties. There is no primary source material to say one way or the other.