I will investigate the leads and see where I end up. At the moment I think that the Haresfield link may be the more probable one but I'll do some more research first.

Baptism at Haresfield

Charles COOK 29 October 1837 - parents William (labourer) and Mary - address: Standish, Coldthorpe

Looking for marriages of ORGAN's at St John the Baptist, Gloucester

27 March 1834

Charles ORGAN - Bachelor, of this Parish
married
Maria STRAIGHT - Spinster - of the same Parish

by Banns

witnesses: Eliza COOKE, Joseph STAIGHT, and Ephraim CLOSE

?

1841 Census, Gloucester St John the Baptists

John ORGAN - 35 - Innkeeper, all born in County
Elizabeth ORGAN -35
James ORGAN - 6
John ORGAN - 4
Thomas ORGAN - 1 (Gloucestershire BDM - christened 1840 - St John the Baptist, mother's maiden name GARDNER)
Aaron BECH? 55
Richard ORGAN, 40 - Ind.

1851 Census, St John the Baptists
London Road
Black Dog

ORGAN

John - 47 - born Glos. Sandhurst
Elizabeth - 44 - born Wotton
John - 14 - solic. Clerk born Herefordshire, Goodrich
Chas - 12 - born Gloucester
Thomas - 10 - born Glos.
Elizabeth - 9
Sarah - 6

CLDS - if you search IGI Batch Numbers, Gloucestershire, Sandhurst, there are children of Thomas & Mary ORGAN. inc.

John ORGAN, christened Sandhurst - 9 January 1803 - Thomas & Mary

Charles ORGAN, christened Sandhurst - 2 June 1811 - Thomas & Mary

Mary Ann ORGAN, christened Sandhurst - 19 July 1807 - Thomas & Mary, (however, there is a death at Sandhurst of a Mary Ann ORGAN aged 30 - 20 June 1836)

Elizabeth ORGAN - 24 May 1795

Gloucestershire Marriage Index pre 1800

Marriage at Sandhurst 15 January 1794

Thomas ORGAN (of Haresfield) married Mary ALLEN

Gloucestershire Burial Index

Sandhurst

Thomas ORGAN age 70 - 12 April 1832 c1762
Mary ORGAN - age 72 - 18 August 1837 c1765

JOHN ORGAN
--------------------------------------------------------
---------------------------------------------------------
Marriages:
Spouse: ANN COOK
Marriage: 18 JUN 1799 Painswick, Gloucester, England
--------------------------------------------------------------
Messages:
Record submitted by a member of the LDS Church.
The source films cannot be sent to family history centers and have limited access
at the Family History Library. A family group record for this family may be in the Family
Group Record Collection; Archive Section. (See the Family History Library Catalog for
the film number.) These records are alphabetical by name of the father or husband.
--------------------------------------------------------------
Source Information:
Batch Number: A456593
Sheet: 00
Source Call No.: 456593 Type: Book

1841
John Organ abt 1775 Gloucestershire, England Cranham, Gloucestershire
Ann Organ abt 1776 Gloucestershire, England Cranham, Gloucestershire
William Riden abt 1816 Gloucestershire, England Cranham, Gloucestershire
Mary Riden abt 1817 Gloucestershire, England Cranham, Gloucestershire
Eleanor Riden abt 1840 Gloucestershire, England Cranham, Gloucestershire

I found the marriage between Mary ORGAN to William COOKE (on this website) on 7 May 1837 in Gloucester St. John the baptist.

The witnesses were:
Harriet Organ
John Organ
Ephraim Close (clerk of the parish?)

I have succesfully traced William COOKE who originated from Standish (hamlet of Coldthrop/Colethrop) and his ancestry thanks to a family bible.

However, I have drawn a blank with Mary ORGAN.
From the 1841 census, (with the surname COOK), she is listed as 35 in Standish, however this only provides a range of birth dates due to rounding.

I believe that she died in 1843 (as there is a death on the BMD in 1843 of a Mary Cooke), however I have not confirmed this with the certificate yet, although by 1852 William had married Mary Ann HAWKINS. The family then moved from Standish to Cheltenham after William's mother's death. This movement is confirmed by both the later censuses and family memory (as Williams' daughter Annie COOKE, who married William HOOPER, lived until 1927).

William was a market gardner by trade and had the following children (with Mary ORGAN; Charles (b. 1837), Annie (b. 1840) and Cornelius (b. 1842).

What I would like to know is, if anyone has any connection or any idea of Mary's parent's or ancestry or if Harriet and John are her siblings/parents or any relation at all!

I've done quick searches on the 1841 census for Harriet and John but haven't found any targets to investigate.