According to the unsourced, and no longer available, Ancestry trees listed below Joan de Nash or DeNash was born in 1429 in Launceston, Cornwall, and died in 1454.
Research Notes
Hasted in his 1798 History of Kent stated that she was the wife of Andrew Hawkins, who lived in the early 1300s.[1] There appears to be no basis for this in primary sources, and indeed the primary source for her basic existence is yet to be discovered (if there is one.) Various recent internet genealogy sites have turned her into the mother of Margaret Hawkins (fl. ca. 1480), which is utterly baseless and chronologically impossible.
Since we do not know who she actually was, it is impossible to guess when she lived, but it would presumably be some time in the 1300s. Hasted's information would place her sometime in the early 1300s, though it is possible Hasted confused her with Joan, the wife of a supposed son of Andrew given in an apparently fraudulent pedigree[2], so she might be based on a real person who lived it the late 1300s.
Sources
↑ Edward Hasted. "Parishes: Boughton under the Blean," in The History and Topographical Survey of the County of Kent: Volume 7, (Canterbury: W Bristow, 1798), 2-19. British History Online, accessed October 1, 2018, http://www.british-history.ac.uk/survey-kent/vol7/pp2-19.
↑ Philipot, J. The visitation of Kent: taken in the years 1619-1621. London, 1898, p. 203 Hathi Trust.