There we not many other 90+ year old women in Westbury around in 1911-1915, so I think you have detailed the correct person. Going by the "father's" name of Jasper Selwyn on the 1838 marriage this would be her baptism with some revealing details.

Record_ID: 31845
Entry_Number: 209
Year: 1819
Month: Apr
Day: 4
Parents_Surname: STEVENS
Child_Forenames: Charlotte Selwyn
Fathers_Forenames: [not stated]
Mothers_Forenames: Mary
Mothers_Surname:
Residence: Flaxley
Occupation: [not stated]
Officiating_Minister: J Turner Curate
Event: Baptism
Memoranda: Base daughter born to Maid Servant
Notes:
Register_Reference: P110 IN 1/5
Page_Number: 27
Parish_Chapel: Littledean

1901 Census, Westbury on Severn,

James REYNOLDS, Head, Mar, 52, Journeyman Carpenter, b. Glos. Westbury on Severn
Esther, Wife, Mar, 56, b. Glos. Westbury on Severn
Charlotte DAVIS, Mother-in-Law, Wid, 82, b. Glos. Flaxley

1891 Census, Westbury on Severn,

Robert (Harper?) DAVIS, Head, Mar, 57, General Labourer, b. Westbury on Severn, Glos.
Charlotte, Wife, 72, b. Flaxley, Glos.
Harry MARSHALL, Grandson, S, 15. National School Pupil Teacher, b. Birmingham Warwickshire

1881 Census, Westbury on Severn,

Robert DAVIS, Head, Mar, 47, Sawyer, b. Glos. Westbury on Severn
Charlotte, Wife, 61, b. Glos. Flaxley
Harry MARSHALL, Grandson, S, 5, Scholar, b. Birmingham

1871 Census, Westbury on Severn, Wintles Hill

Robert DAVIS, Head, Mar, 37, Labourer, b. Westbury on Severn, Glos.
Charlotte, Wife, 51, b.Flaxley, Glos.
Caroline MARSHALL, Dau, Mar, 25, Labourer’s Wife, b. Westbury on Severn, Glos.
George MARSHALL, Grandson, S, 4 months, Scholar, b. St Philips and Jacobs Parish Bristol

Record_ID: 19259
Entry_Number: 373
Year: 1868
Month: Aug
Day: 18
Grooms_Surname: DAVIS
Grooms_Forenames: Robert Harper
Grooms_Age: Of Full Age
Groom_Condition: Batchelor
Grooms_Occupation: Labourer
Grooms_Residence: Westbury
Grooms_Fathers_Surname: Davis
Grooms_Fathers_Forenames: James
Grooms_Fathers_Occupation: Inn Keeper
Brides_Surname: HOPES
Brides_Forenames: Charlotte
Brides_Age: Of Full Age
Brides_Condition: Widow
Brides_Occupation: [not stated]
Brides_Residence: Westbury
Brides_Fathers_Surname: [Not stated]
Brides_Fathers_Forenames: [Not stated]
Brides_Fathers_Occupation: [Not stated]
Licence_or_Banns: Banns
Date_of_Banns: [not stated]
Signature_or_Mark: He signs She marks
Witness_1: James Davis
Witness_2: Harriet Davis
Other_Witnesses:
Officiating_Minister: Christopher Jay Jones Vicar
Event: Marriage
Memoranda:
Notes:
Register_Reference: P354 IN 1/7
Page_Number: 187
Parish_Chapel: Westbury on Severn
Soundex_Groom: D120
Soundex_Bride: H120

1861 Census, Westbury on Severn, Wintles Hill

Charlotte HOPES, Head, Wid, 42, Ag. Lab, b. Gloster, Flaxley
George, Son, Un, 21, Wheelwright’s Ap., b. Gloster, Westbury on Severn
Esther, Dau, Un, 17, Serv. out of situation, b. Gloster, Westbury on Severn
James, Son, 12, Ag. Lab. b. Gloster, Westbury on Severn
Mary DREW, Lodger, Un, 17, Dressmaker, b. Gloster, Westbury on Severn

1851 Census, Westbury on Severn

James HOPES, Head, Mar, 37, Ag. Lab., b. Gloster, Westbury
Charlotte, Wife, 31, b. Gloster, Westbury
Esther, Dau, 7, Scholar b. Gloster, Westbury
Caroline, Dau, 5 Scholar, b. Gloster, Westbury
James, Son, 2, b. Gloster, Westbury

Record_ID: 8693
Entry_Number: 5
Year: 1838
Month: Dec
Day: 26
Grooms_Surname: HOPES
Grooms_Forenames: James
Grooms_Age: full age
Groom_Condition: Bachelor
Grooms_Occupation: Collier
Grooms_Residence: Little Dean
Grooms_Fathers_Surname: HOPES
Grooms_Fathers_Forenames: James
Grooms_Fathers_Occupation: Labourer
Brides_Surname: STEVENS
Brides_Forenames: Charlotte
Brides_Age: full age
Brides_Condition: Spinster
Brides_Occupation: [not stated]
Brides_Residence: Little Dean
Brides_Fathers_Surname: SELWYN
Brides_Fathers_Forenames: Jasper
Brides_Fathers_Occupation: Farmer
Licence_or_Banns: Banns
Date_of_Banns: [not stated]
Signature_or_Mark: Both mark
Witness_1: Mark of James Saysell
Witness_2: Mark of Sophia Saysell
Other_Witnesses:
Officiating_Minister: J. Parsons Curate
Event: Marriage
Memoranda:
Notes:
Register_Reference: P 110 IN 1/10
Page_Number: 3
Parish_Chapel: Littledean
Soundex_Groom: H120
Soundex_Bride: S315

Record_ID: 46819
Entry_Number: 125
Year: 1852
Month: Dec
Day: 18
Surname: HOPES
Forenames: James
Residence: Westbury
Age_at_death: 39
Officiating_Minister: T L Montifine
Event: Burial
Cause_of_death:
Memoranda:
Notes:
Register_Reference: P 354 IN 1/16
Page_No: 16
Parish_Chapel: Westbury on Severn
Soundex: H120

SEWING SHIRTS AT 96

Mrs Davies, Westbury on Severn, 96 years of age is devoting her time to making shirts for soldiers. She scorns the use of glasses, and retains her full faculties. Her daughter is 72 and both are pensioners.

A quick search makes me think that this is her and her daughter on the 1911 census, then going back it starts to get more involved, if anyone else fancies having a look to sort out the family background please do.

Census reference RG14PN15211 RG78PN920 RD323 SD1 ED3 SN95

James Davis Reynolds Head Married Male 62 1849 Glos Westbury on Severn Carpenter
Esther Reynolds Wife Married Female 67 1844 Glos Westbury on Severn -
George Albert Reynolds Son Single Male 28 1883 Glos Westbury on Severn General Labourer
Charlotte Davis Mother In Law Widow Female 92 1819 Glos Flaxley Glos Old Age Pensioner

This is Charlotte's burial I believe

Record_ID: 285967
Entry_Number: 251
Year: 1915
Month: Oct
Day: 12
Surname: DAVIS
Forenames: Charlotte
Residence: Wintle's Hill Westbury on Severn
Age_at_death: 96 years