You've probably already figured this out but in case you haven't I believe that Jane Turner, is the Jane Clark, daughter of Henry's full sister Mary Towles and John Clark who married Fleming Turner of Buckingham. Issue named in Henry Towles will.
John Clark, son of William Clark and his first wife Ann James, born 19 February 1741, Clark's Mountain for whim it is said that landmark was named; married Mary Towles, daughter of Stokely Towles and his second wife Jane Sparks; died intestate in that neighborhood on 28 October 1831. From the will of Henry Towles, supra, and other records the names of his children and grandchildren appear as follows: 1. William Clark, born 9 October 1766 married Lucretia Clark 2. Mary Clark, born 1768 married Thomas Wells 3. John Clark, born 1770, died without issue 4. Henry "Harry" Clark, born February 1773 married first Ann Grasty, second Elizabeth Smith 5. Jane Clark married Fleming Turner <<<<<<<<<<<<<< 6. Abner Clark, died sine prole 7. Reuben Clark, died sine prole 8. Edmund Clark, died sine prole 9. James Clark married Elizabeth T. Murphy 10. Lucy Clark, never married 11. Sarah Clark, never married Towles and Clark Families by William B. Newman, Washington, D.C. published in Genealogies of Virginia Families from Tyler's Quarterly Historical and Genealogical Magazine, Volume III, page 594-596