Her birth on the Quaker index of such:

First name(s) Mary
Last name Hurnard
Birth year 1770
Birth date 26 Sep 1770
Birth place as transcibed Witham
Birth county as transcribed Essex
Father's first name(s) Jno
Mother's first name(s) Jane
Meeting place Witham
Monthly meeting Witham
Quarterly meeting Essex
County Essex
Country England
Archive reference RG6/1292
Description ESSEX: Monthly Meeting of Witham
Record set England & Wales, Society Of Friends (Quaker) Births 1578-1841

The Text of the entry is:

“Boreham: Mary Hurnard Daughter of John & Jane his wife was born 26 9 1770”

(She also had a brother John on the same page born on 15 Aug 1765.)
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The transcription from an abstract of her Quaker death record:

First name(s) Mary
Last name Docura
Age 67
Birth year 1769
Death year 1836
Death date 08 Nov 1836
Burial year 1836
Burial date 13 Nov 1836
Burial place as transcibed Coggeshall  [recte: Kelvedon, Essex]
Burial county as transcribed Essex
Meeting place Coggeshall
Monthly meeting Coggeshall
Quarterly meeting Essex
County Essex
Country England
Spouse's first name Thos
Archive reference RG6/53
Description ESSEX: Monthly Meeting of Coggeshall: Burials
Record set England & Wales, Society Of Friends (Quaker) Burials 1578-1841
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It is noteworthy that she had he death in the quaker records and without any hint that she was not a member, as in her husband’s record three years earlier.  I suspect that this was because she wished to have her husband buried in the Quaker burial ground as his family had been and as she intended to be; sensibly they allowed this to happen.
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No will can be found for her.
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FindMyPast has three images of records for this marriage:

1. The marriage itself, taken as a copy for the Monthly Meeting in Essex either at Chelmsford or at Witham.

2. A second copy, slightly different, of the above.

3. An abstract of the Monthly Meeting record for the Quarterly meeting records.

The Text of the Monthly meeting record is:

Thomas Docwra of Latchingham in the County of Essex, Farmer Son of of Joseph Docwra late of Kelvedon in the said County, Miller and Patience his wife him surviving and Mary Hurnard Daughter of John Hurnard of Boreham in the County aforesaid and Jane his wife . . . .
Having declared their Intentions of taking each other in Marriage before several Meetings of the People called Quakers in Chelmsford and Witham the proceeding of the said Thomas Docwra and mary Hurnard after the Enquiry  and delibrate Consideration thereof were allowed by the said Meetings, they appearing clear of all others and having consent of parents and others concerned.
Now these are to certify all whom it may concern, that for the accomplishing of their Marriage this second day of the first Month called January in the year One Thousand seven Hundred and Ninety-four they the said Thomas Docwra and Mary Hurnard appeared at a publick Assembly of the aforessaid People and others in their Meeting House at Chelmsford and he the said Thomas Docwra taking the said Mary Hurnard by the Hand, did openly and solemnly declare as followeth, Friends, in the fear of the Lord and before this Assembly I take this my Friend Mary Hurnard to be my wife, promising through divine assistance to be unto her a loving and faithfull Husband until it shall please the Lord by death to separate us. . .
And the said Mary Hurnard did then and there in the said Assembly Declare as followeth Friends, In the fear of the Lord and before this Assembly I take this my Friend Thomas Docwra to be my husband promising through Divine assistance to be unto him a loving and faithfull Wife until it shall please the Lord by Death to separate us.
And the said Thomas Docwra and mary Kurnard as a farther Conformation thereof and in Testimony thereunto did then and there to these presents set theri Hands   Thomas Docwra   Mary Hurnard
We who were present among others at the above said Marriage have also subscribed our Names as Witnesses thereunto the Day and Year above written:
Jonathan Allen Sarah Edwards Junr
Priscilla Knight Junr
William Knight Junr
Samuel Thom
Susannah Richardson
Sarah Richardson
Daniel Richardson Junr
Robert Richardson
John Marriage
Elizabeth Wood
William Knight
Trove(?) Coppey
Joseph Marriage
Robert marriage
Thomas Marriage
Francis Hill
John Drewitt
Robert Greenwood Junr
Joseph Marriage Junr
Samuel Clark
Joseph Tilney
Henry Edwards
Samuel jasper
William Marriage
John Marriage
Joseph Wood
Thos Puplett
Thos Bayley
Ann Cathpool
Sarah Shellon
Mary Greenwood
Elizabeth Puplett
Mary ® Marriage
Thomas Puplett
Susannah Puplett
Susannah Greenwood
Hannah Waring
Mary Marriage junr
Daniel King
John Mayott

Relatioons:
John Hurnard
Patience Docwra
Jane Hurnard Junr
John Hurnard Junr
Robert Hurnard
Ann Docwra
Patience Messer
John Messer
John Mace.
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The Quarterly Meeting wording was:

The Second Day of the First Month, One Thousand Seven Hundred and Ninety four - Thomas Docwra of Latchingdon in the County of Essex - Farmer, Son of Joseph Docwra ... late of Helvedon in the County of Essex - Miller, deceased ... and Patience his Wife, she surviving and Mary Hurnard Daughter of John Hurnard of Boreham in the County of Essex, Shopkeeper and Jane his wife, were married in a publick Assembly of the People called Quakers, in Chelmsford in the County of Essex.
                  Clerk to the Quarterly-Meeting

N.B. A Copy of the marriage-certificate, at full Length, is recorded in Monthly-Meeting
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