I think I see where the name Mary got incorporated into this.
Taylor, Edward: Est. - 4 May 1708. By Margaret Taylor. Wm. Gray, Timothy Thropp, Wm. Harris. Book 5 p 392
Taylor, Edward: Est. - Mary Taylor, admr. 19 July 1727. Thos. Holt, Christopher Clinch, Thos. Edwards. Bk. 7 p 740
Wills and Admins of Surry Co, E T Davis p 127
The Edward Taylor/Mary Taylor record was 19 years after the estate records for Edward Taylor by Margaret Taylor. Certainly not the same Edward Taylor. The later Edward Taylor could certainly have been a son. Christopher Clinch had married Hannah Taylor, daughter of Margaret -- Taylor Harris.
You're right that there is no proof that Margaret -- Taylor Harris was a Gray, and it would be wrong to record her as a Gray without proof. There was certainly a close association with the Grays, but that's all that can be proven unless/until more records are found.
It is interesting that William Gray's name appeared on the 1708 record for Edward Taylor's estate. William Gray and William Gray Jr were witnesses to the 1720 will of William Harris, and William Gray was a witness to the 1721 will of Margarett -- Taylor Harris.
Margaret -- Taylor Harris's daughter Margaret Taylor m1 William Judkins, son of Robert Judkins I d 1693 Surry. The 1693 will of Robert Judkins named son William, son Robert, dau Elizabeth, dau Sarah, wife Elizabeth. He may have been previously married to a daughter of Edward Pettway as Pettway's 1690 will left a breeding yew to Sarah, daughter of Robert Judkins, but no relationship to Sarah or Robert Judkins was stated. Pettway also named his daughter Elizabeth, wife of Samuel Judkins (II). Robert Judkins I and Samuel Judkins II were brothers.
Margaret Taylor Judkins m2 Barlett Moreland. His will was wit by William Gray and referred to land in York Co that came to me by marriage with my first wife. I know Moreland's last wife was Elizabeth Briggs who later married James Vaughan. Was Margaret Taylor Judkins his first wife or was there a wife before her? There's a clue to follow - the land in York Co.
Robert Judkins (II), Nicholas Maget, and Samuell Maget witnessed the 1719 will of William Gray.
Nicholas Maget's wife Ann was previously the wife of John Taylor, son of Margaret -- Taylor Harris whose will named son John Taylor and wife Ann.
Nicholas Maget's 1743 will named wife Ann, sons Nicholas and Samuel Maget, son-in-law Robert Judkins (II)
Robert Judkins I was one of 3 known sons of Samuel Judkins I (will written 1671, pr 1672) and Lydia. Lydia m2 Thomas Pitman and died by 1678/9. Her sons by Samuel Judkins I were Samuel Judkins II (eldest), Robert Judkins I, and Charles Judkins I.
There is no proof that Lydia was a Gray, but the name Gray did appear frequently as a given name in the Judkins descendants. Lydia was NOT the daughter of William Gray and the sister of John Gray as you will frequently see. John Gray's will leaving household goods to sister Lidie was written in 1708, and Lydia -- Judkins Pitman was dead long before that.
Robert Judkins I and Samuel Judkins II (names recorded as Jerkins rather than Judkins) were granted land in Surry on 20 April 1685 - 200 acres on the east side of Grays Creek. Escheat land, formerly granted to Thomas Laines, deceased.
I have found no grant to a Thomas Laines and I believe the name was recorded in error and should have been Thomas Gray.
Grey, Thomas. grantee.
Land grant 7 June 1642.
Location: James City County.
Description: 100 acres on the East side of Greys creek adjoining a dividend of 600 acres of Land now in the possession of the said Grey. Beginning at a little Cross Creeke at the Southward end of the --- of the said 600 acres and running up Southerly along by the side thereunto the head thereof abutting easterly upon Grays Creek and northerly upon the land of the said one hundred acres of marsh being due unto him the said Thomas Grey by and for the transportation of ?? persons into this colony.
Source: Land Office Patents No. 1, 1623-1643 (v.1 & 2), p. 787 (Reel 1).
Surely this 100 acre grant didn't adjoin itself. The "said 100 acres" that it adjoined must have been another tract. The description of land on the E side of Gray's Creek agrees perfectly as does the number of acres.
The land wasn't inherited from Thomas Gray, so we still have no proof that Lydia -- Judkins Pitman was a Gray. Lydia was born so early that IF she was a Gray, she would have to be a daughter of Thomas Gray, not one of his sons.
Robert Judkins left his half of the land (100a) to son William Judkins who left it to his daughters Elizabeth and Hannah. Elizabeth Judkins Berriman and husband John Berriman later sold their 50 acres to Samuel Judkins II. Prior to that, Samuel Judkins III, Henry Jones and wife Catherine (Judkins), and William Dennis (whose mother was apparently a daughter of Samuel Judkins II - Henry Jones' 1733 will referred to William Dennis as his "cousin") sold their 100a to Thomas Crews. This was some time prior to Jan 21, 1727/8 when the land was mentioned in Crews' will. Thomas Crews left to his son John Crews a tract of land called Gray’s which he had bought from Henry and Catherine Jones, William Dennis, and Samuel Jenkins, being 100 acres. No deed has been found. (The name Judkins was frequently misrecorded as Jenkins or Jerkins.)
1730, April 14 - Indenture John Berryman, wife Elizabeth, to Samuel JUDKINS. 1/2 of a tract on Gray's Creek; belonged to Robert Judkins, who Willed it to a son, William Judkins, from whom it descended to two daughters, Elizabeth and Hannah. Bounding on land Henry Hart sold Robert Pettway, and on Samuel Judkin's land.
Witnesses: Robert BARHAM, Jr., William Edwards
Surry W&D Book 1730/38, p.8
Either this is referring to old lines (since the 100 acres that had belonged to Samuel Judkins II had been previously sold to Crews) or Samuel Judkins III had purchased the other 50 acres from Hannah Judkins prior to this deed. No record for Hannah's 50 acres has been found.
So you're entirely right that there are no records to prove Margaret -- Taylor Harris was a Gray. There are also no records to prove that Lydia -- Judkins Pitman was a Gray. But there are certainly records indicating a close connection involving these families, and perhaps someday a record will be found that will prove or disprove a connection.