"Some researchers claim she is Jane Bolling. This person is on the list of dubious Pocahontas descendants, Jane Bolling, daughter of Jane Rolfe and Col. Robert Bolling, sister of Col. John Bolling, and later wife of Rev. James Clack. There are plenty of Jane Bollings, but Col. John Bolling was the only child of Jane Rolfe. Rev. Clack certainly married someone who had his three children, but she wasn't the daughter of Col. Robert Bolling and Jane Rolfe. Here is a [reasoned argument to the contrary though].
It is said that Jane was born 1675 in Kippax, Charles City, Gloucester Co VA, and that she died 24 Aug 1714, Gloucester Co VA, age about 39, probably at the birth of her youngest child.
She is not buried beside her husband. There is speculation that this may be the case because she may have 'married again after James' death, or perhaps moved to another place. However, neither of these is possible, if James' and Jane's death dates are correct.
Several researchers have suggested that the Rev James Clack married "Jane Bolling, daughter of Col Robert Bolling and Jane Rolfe" (granddaughter of Matoaka, better known as Princess Pocahontas, andJohn Rolfe). Unfortunately, we have seen no evidence that "Jane Bolling" ever even existed, and it appears that Jane Rolfe had just one child (John Bolling) during her brief marriage to Robert Bolling before her death.
It has also been suggested that she may have been Jane Maclin. James' granddaughter Sarah Clack married William R Maclin. Could Jane Maclin have been William's mother or grandmother? Jane could have been a widow when/if she married James Clack. We have no information about William R Maclin's parents or birthdate." - Edler
Another theory on the identity of Jane from Bolling Family Genealogy Forum at Genealogy dot com forum 
↑ Back to first child of Colonel Rober Bolling 26 Dec. 1646 London-17 July 1709 Charles City,VA and unknow wife in London, England in 1674: she is a daughter, Jane Bolling born 1674 London,England wed to Rev. James Clack circa1655 Wiltshire, England, s/o William Clack and Mary Spencer, of Marden Parrish, Wiltshire, England. Mother of Jane 1674 in London, Eng. is unknown. Jane 1674 lived until after 1726 in Colonial America.
Source of data: Bolling-Bowling USA Roots Tree, "Kings of Sheltered Meadows" by John P. Sullivan, P.O. Box 7000-739, Redondo Beach, CA 90277
It may be possible to confirm family relationships with Jane 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 Jane:
Bolling-439 and UNKNOWN-45510 appear to represent the same person because: No direct evidence has been found to definitely establish the maiden surname of Jane, wife of Rev. James Clack. It is inferred from circumstantial evidence that she was Jane Bolling. There has been no sources located to prove this fact. (Virginia Magazine of History and Biography, Vol. 21, p. 326).