TFPL, Oct 2019: A marriage can be found in 1803 between a Susan Sewel and a Thomas Forster (no Furly) in Cambridge but I do not think this is them.  (Try again in a few more years in case a few more records have been added?  (If I am apared!))

She gave birth in 1808, so she was born before 1793.  She could easily have been born anywhere between 1773 and 1793, earlier, even.  She was a widow in 1828.  So she either married again after 1828 or she died as Susanna Forster.  As her daughter was married at Binfield, this implies that she and Marian had been living there.  So, if she married again I would expect her to marry or live possibly within Berkshire where she had been living and where her daughter was now living or at least within the home counties.  There is one marriage that fits this picture, that of a Susanna Forster and a Robert E Knight in 1833 in Newington St Mary, Surrey.

In the 1841 census there are a Robert and Susanna Knight living with a daughter Eliza in Enfield Middlesex, but Eliza was 15 so too too old for that marriage.  No other household even begins to look like hers.

And no burial or death can be found for her within even a loose version of the above criteria.
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I have found two births to Thomas Furl(e)y and Susanna Forster on FindMyPast:

1801, Aug 6: Bapt of Edward Forster in Hackney
1808, Dec 29, Bapt of Marian in Hackney
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Also in the 1831 census I have found Susanna Forster, widow, as the mother-in-law of Rev A F Lloyd, rector of Instow, Devon, and mother of Harriet Lloyd who was born in 1806 in Hackney.  Susanna herself was recorded as 84, so born in 1767 and at West Ham, Essex.

But I can't find Harriet Forster's birth anywhere around 1806.
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All the above led to finding her marriage and her maiden name of Williams.
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And then to her baptism:

Record set Essex Baptism Index 1538-1920
First name(s) Susanna
Last name Williams
Baptism year 1766
County Essex
Country England
Place West Ham, All Saints
Mother's first name(s) Jane
Father's first name(s) Thos
Father's last name Williams
Baptism date 30 Apr 1766
Archive
Essex Record Office
Archive reference D/P 256/1/3
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All the above confirms the information on the 1851 census, so I'm now regarding that as for her and her daughter at Rectory, Instow, Barnstaple, Devon:

First name(s)  Last name  Relationship  Marital status  Sex  Age  Birth year  Occupation  Birth place
A F Lloyd Head Married Male 56 1795  Rector Of Instow  Ireland
Harriet Lloyd Wife Married Female 45 1806 Wife Hackney, Middlesex
Benjamin Ferney Lloyd Son - Male 14 1837 - Instow, Devon
Thomas F F Lloyd Son - Male 6 1845 - Instow, Devon
Harriet Mary Lloyd Daughter Unmarried Female 21  1830  -  Instow, Devon
Isabella Lloyd Daughter Unmarried Female 20 1831  -  Instow, Devon
Emily Lloyd Daughter Unmarried Female 18 1833  -  Instow, Devon
Adelaide Lloyd Daughter Unmarried Female 16 1835  -  Instow, Devon
Hannah Lloyd Daughter Unmarried Female 13 1838  -  Instow, Devon
Marian Lloyd Daughter - Female 1 1850 - Instow, Devon
Susannah Forster Mother-In-Law Widow Female 84  1767  -  West Ham, Essex
Julia E Boteler Visitor Unmarried Female 12 1839  -  Wickham, Kent
Annie A Boteler Visitor Unmarried Female 10 1841  -  Wickham, Kent
Jane Beck Visitor Unmarried Female 30 1821 Ladys Maid  Tiverton, Devon
Eliza Beck Servant Unmarried Female 22 1829 Nurse  Barnstaple, Devon
Mary Jane Cairn Servant Unmarried Female 18  1833  House Servant  Instow, Devon
Sophia Symons Servant Widow Female 26 1825 House Servant  Tawstock, Devon
Susanna Braund Servant Unmarried Female 12 1839  House Servant  Fremington

Ref:
Archive reference   HO107
Piece number        1893
Folio               531
Page                17
Combined:           HO107, piece 1893, folio 531, p. 17
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All this then led to finding her burial at Instow, but to no death registration:

First name(s)   Susanna
Last name       Forster
Age             91
Birth year      1766
Death year      1857
Burial year     1857
Burial date     05 Dec 1857
Denomination    Anglican
Burial place    Instow
Residence       Rectory, Instow
County          Devon
Country         England
Archive         South West Heritage Trust
Record set      Devon Burials
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Her will showed that her son-in-law was Arthur Forbes Lloyd.

Her will makes it categoric that all the above relationships are correct.
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Her probate index:

Will of Susanna Forster, Widow of Instow , Devon
Reference: PROB 11/2261/447
Description: Will of Susanna Forster, Widow of Instow , Devon
Date: 29 December 1857

Her will has been ordered to see if she listed any of her grandchildren.
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In her will she lists:

her late husband Thomas Furly Forster
Her daughter Dusanna Dorothy Fernandez,
Her son-in-law Arthur Forbes Lloyd
Elliott Morres, brother to her son-in-law Thomas Morres who had married her daughter Marian,
her daughter Marian Morres,
Her granddaughter Emily Morres,
Her daughter harriet Lloyd

Her executors were to be her three daughters, Susanna Dorothy, Harriet and Marian.

Signed and dated 21 March 1850.
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Their marriage abstract:

First name(s)            Thomas Furley
Last name                Forster
Name note             -
Marriage year            1788
Marriage date            26 Jul 1788
Marriage place           Walthamstow
Spouse's first name(s)   Susannah
Spouse's last name       Williams
County                   Essex
Country                  England
Record set               England Marriages 1538-1973
Category                 Birth, Marriage, Death & Parish Records
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Phillimore's Marriage Registers records that they had a marriage licence as:

"Thomas Furley Forster & Susanna Williams, p. St Botolph, Aldersgate, London , lic 26 July 1788."
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