I don't know how much I can help you, but I am also looking at this family.
Ann Jenkinson (who married Claud Vallott) had a sister Mary Jenkinson who married John Nash on July 12, 1690 in Middlesex County, VA.John and Mary (Jenkinson) Nash were my direct ancestors.
Just yesterday I started piecing together the Nash / Jenkinson / Fisher connections via several entries in the book "Middlesex County Virginia Wills & Inventories 1673-1812 and other court papers".Although these entries are just abstracts which can be confusing, it led me to various postings on the internet which help make some sense out of all of it.
It appears that Ann and Mary Jenkinson's mother was Dorothy (maiden name unknown), who had remarried to Christopher Fisher who died in June of 1688.John Nash was a witness to Dorothy's will on June 30, 1688.Dorothy apparently died shortly after this, as indicated by the entry in the "Wills & Inventories" book which says "Probate of the will of Mrs. Dorothy Fisher, decd., is granted Mary Jenkinson and Ann Jenkinson.3 Sep 1688 "
I have not found any reference to Ann and Mary's father Thomas Jenkinson in any of my Middlesex County sources, and I am interested in how his name and approximate year of birth became known.Do you have anything regarding that?