She was discovered first in the will of her father, after his death in 1854.
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Her baptism:

First name(s)           Caroline Mary
Last name               Powys
Birth date/age          22 Apr
Baptism year            1836
Baptism date            02 Jun 1836
Parish                  Highgate, St Michael
Father's first name(s)  Robert Vernon
Mother's first name(s)  Jane
Relationship            Daughter
Occupation              Lieutenant, E.I.C.
Residence               London
County                  Middlesex
Country                 England
Record set              Middlesex Baptisms 1543-1876
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Later, the image, thanks Ancestry, of the Register was found, transcript by me:

>             Camden  >  St Michael Highgate  >  1835-1862

“                          Page 44
“BAPTISMS solemnised in the Parish of Saint Michael Highgate
“  in the County of Middlesex in the Year 1836.
“. . . .
“When Baptised:       June 2nd. [ 1836 ]
“When born:           22nd. April [ 1836 ]
“No:                  350
“Child’s Forename:    Caroline Mary, dr. of
“Parents’ Forenames:  Robert Vernon & Jane
“Parents’ Surname:    Powys
“Abode:               London
“Profession:          Lieutenant E.I.C.S.
“Celebrant:           J. Drummond
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In 1851 she and two of her brothers, though mistranscribed as ‘Powies’, were living with Caroline Beckett, their aunt in St Pancras, London:

First name(s)  Last name  Relationship  Marital status  Gender  Age  Birth year  Occupation  Birth place
Caroline         Beckett  Head  U  F  56  1795  Proprietress Of Houses  Enfield, Middlesex
Harriett         Beckett  Niec  U  F  17  1834  At Home                 India
William Hy       Beckett  Neph  U  M  14  1837  Scholar                 India
Tempe Susan      Beckett  Niec  U  F  11  1840  At Home                 India
Robert Horace    Powys    Neph  U  M  24  1827  Merchants Clerk         India
Caroline Mary    Powys    Niec  U  F  14  1837  At Home                 At Sea
Edward Atherton  Powys    Neph  U  M  13  1838  Scholar                 St Pancras, Middlesex
Martha           Willis   Serv  U  F  30  1821  Servant                 Devizes, Wiltshire
Ann              Scare    Serv  U  F  24  1827  Servant                 Lambeth, Surrey
Charlotte        Siplep   Serv  U  F  23  1828  Servant                 Marlborough, Wiltshire

Address & Ref:
Street [19]        Hunter Street
Parish             Saint Pancras
City               Marylebone
County             London, Middlesex
Archive reference  HO107
Piece number       1495
Folio              120
Page               25

Composite:         1851 ref: HO107, piece 1495, folio 120, p. 25
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In 1861 she was still with her aunt, Caroline Beckett.  Her birth was still stated to be ‘At Sea’.
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She next appears in the 1891 census as a boarder with a family of Andersons in Paddington, London, but if she was a widow, was she using her maiden name?  If this was her married name, then I have misidentified her:

First name(s)  Last name  Role  Marital status  Sex  Age  Birth year  Occupation  Birth place

Eliza     Anderson  Head  W  F  53  1838  Lodging House Keeper  Westbury, Wiltshire
Evelyn    Anderson  Daur  S  F  18  1873  Useful Help           Brighton
Caroline  Dunning   Niec  S  F  21  1870  Useful Help           Westbury, Wiltshire
Caroline  Powys     Brdr  W  F  55  1836  Living On Own Means   India

Address & Ref:
Street             Burlington Road
Parish             Paddington
County             London, Middlesex
Archive reference  RG12
Piece number       11
Folio              51
Page               28
Combined:          1891 ref: RG12, piece 11, folio 51, p. 28
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Her death index:

Name:                     Age at Death (in years):  
POWYS, CAROLINE MARY      68  
GRO Reference: 1905  M Quarter in CAMBERWELL  Volume 01D  Page 436

No will can be found to corroborate this.
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Her probate index (from FindMyPast):

1905
POWYS Caroline Mary of 99 Woodvale Lordship-lane Surrey spinster died 5 February 1905  Probate London 12 April to Stephen Beckett C.B. retired colonel in the Bengal-staff-corps  Effects £3225 1s. 2d.  Resworn £3832 3s. 3d. and £4035 18s. 3d.

To be ordered when gov.uk comes back into reality.
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A further discover on FindMyPast’s site was the documents from the Indian High Court of Fort William, Bengal which included a full transcription, signed to the effect that it was a good copy of her English will.  So I don’t need to pay 30 shillings to the disparaged gov.uk that has been falling apart recently (we are now in March 2022).

In her will signed on 24 Nov 1891 with a codicil of the 14th January 1905 she appointed her relation Col Stephen Beckett (as above) to be her executor and it was proved in India on 12th August 1905.

In her will she named these relations:

1. Col Stephen Beckett C.B.
2. Her niece Ellen Jane Beatrice Powys daughter of the next named,
3. Her brother Robert Horace Powys and his wife Ellen Elizabeth Powys,
4. Her niece Mary Augusta Mathers, wife of Edward Peter Mathers
5. Her cousin George Batten of No 2 Underhill Rd, Lordship Lane, Surrey
6. Lena Batten, the wife of George Batten,
7. Her cousin Annie Burns,

The Battens I do not know anything about, the may be Beckett relatives and so not Powys descendants.
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