Royal Descents of Famous People @ Has her mother of Helen of Galloway
The cited information was published by 1995, 1996 (Ref: Has her mother of Helen of Galloway) The author/originator was Mark Humphrys.
Source Notes
Based on Burke's Peerage of American Presidents, Burke's
Dormant & Extinct Peerage: Ferrers, Neville, Clifford) &
Burke's Peerage 1970. See notes section for Edward III.