Baptism not found.

I cannot find her death record on FreeBMD.

O Barron in the Northants Genealogy volume, p. 265, gives her birth as in 1808, m. on 3 Apr 1831 and d. on 17 Jun 1840.
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Their children were:

Last name  First name(s)  Year Of Birth  Year Of Death  Year  Location
Causton    Ellen Mary            1832    —              1832  St Botolph Aldersgate, London
Causton    Henrietta Maria       1835    —              1835  London
Causton    Thomas Lilford Neill  1836    —              1836  Highgate, St Michael, Middlesex
Causton    Ann Elizabeth         1837    —              1837  Highgate, St Michael, Middlesex
Causton    Edward Atherton       1838    —              1838  Highgate, St Michael, Middlesex
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Her burial (no death registration found):

First name(s)       Frances Hester
Last name           Causton
Age as transcribed  31
Birth year          1809
Death year          1840
Burial year         1840
Burial date         17 Jun 1840
Occupation          Clerk
Parish              Highgate, St Michael
County              Middlesex
Country             England
Relationship        Wife Of Thomas Henry And 5Th Daughter Of Lord Lilford
Notes               Biblical Text
Source              Middlesex Burials & Memorial Inscriptions
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February, 2022, TFPL: Thanks to Ancestry, an image of the burial register has been found, transcript by me:

“                           Page 78.
“BURIALS in the Parish of Saint Michael Highgate
“  in the County of Middlesex in the Year 1841 & 41
“. . . .
"Name:         The Honble. Frances Hester Causton
“No:           628
“Abode:        Highgate
“When buried:  Jun 24th 1840
“Age:          32
“Celebrant:    B(?). Harvey
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In The Globe of 22 June 1840, there was this notice:

“DEATH OF THE HON MRS CAUSTON.  The demise of this lady took place at Highgate vicarage, on Thursday last, in her 28th year.  She was the Hon. Frances Hesther Powys, fifth daughter of the late, and sister to the present Lord Lilford, on of the lords in waiting to the Queen.  She married, 5th April, 1831, the Rev Thomas Henry Causton, by whom she has left an infant family.”

Not sure about this birth year of c.1813.
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Their marriage abstract detail in the London Courier and Evening Gazette of 9th April 1831:

On Tuesday, the 5th instant, at St John’s Hampstead by the Hon, and Rev. Horace Powys, the Rev. Thomas Henry Causton, vicar of St Botolph, Aldersgate, and eldest son of the Rev. Dr. Causton, Prebendary of Westminster, to the Hon. Frances Hester Powys, fifth daughter of the late Lord Lilford.
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And this Marriage Licence was issued:

“LONDON DIOCESE                 4th April 1831
“
“APPEARED PERSONALLY the Reverend Thomas Henry Causton of the Parish of Saint Botolph Aldersgate in the County of Middlesex Clerk a Bachelor of the life of twenty one years and afterwards

“and prayed for a Licence for the Solemnization of Matrimony in the Parish Church of Saint John Hampstead in the County of Middlesex
between him and the honorable Frances Hester Powys of the said parish of Saint John Hampstead a Spinster of the age of twenty one years & upwards

“and made oath that he believeth that there is n o Impediment of Kindred or Alliance, or any other lawfuyl Cayse, nor any Suit commenced in any Ecclesiastical Court to bar or hinder the Proceeding of the said Matrimony, according to the tenor of such Licence.  And he further made Oath, that the said honourable Frances Hestger Powys hath had her usual Place of Abode within the said Parish of Saint JKohn Hampstead for the Space of Fifteen Days last past.

    [sgnd]       Ellen Mary       T H Causton

Sworn before me
    [sgnd]       John Darlington
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