I have now found a likely baptismal record which is consistent with her age given on the memorial plaque.

Record_ID: 171610
Entry_Number:
Year: 1703
Month: Mar
Day: 2
Parents_Surname: GOUGH
Child_Forenames: Tarey
Fathers_Forenames: Stephen
Mothers_Forenames: Elizabeth
Mothers_Surname:
Residence:
Occupation:
Officiating_Minister: Richard Hall Rector
Event: Baptism
Memoranda: son of. Churchwardens: Nath[aniel] Rudge; Edward Madockes
Notes: Old style date 1702-3
Register_Reference: P220 IN 1/1
Page_Number: 32
Parish_Chapel: Mitcheldean
Soundex: G200

Record_ID: 36714
Entry_Number:
Year: 1730
Month: Jun
Day: 16
Grooms_Surname: STEPHINS
Grooms_Forenames: John
Grooms_Age:
Groom_Condition:
Grooms_Occupation:
Grooms_Residence:
Grooms_Fathers_Surname:
Grooms_Fathers_Forenames:
Grooms_Fathers_Occupation:
Brides_Surname: GOUGH
Brides_Forenames: Tacy
Brides_Age:
Brides_Condition:
Brides_Occupation:
Brides_Residence:
Brides_Fathers_Surname:
Brides_Fathers_Forenames:
Brides_Fathers_Occupation:
Licence_or_Banns:
Date_of_Banns:
Signature_or_Mark:
Witness_1:
Witness_2:
Other_Witnesses:
Officiating_Minister:
Event: Marriage
Memoranda:
Notes:
Register_Reference: P220 IN 1/1
Page_Number: 65
Parish_Chapel: Mitcheldean
Soundex_Groom: S315
Soundex_Bride: G200

Son John (1709-1767), his wife Sarah ? (ca 1747-1800) & their son John & his wives' deaths are marked by a prominent plaque on the wall of the Mitcheldean church,

Near this place lie the remains of
JOHN STEPHENS who departed this life
the 23rd day of April 1767 aged 58 Yrs
And also the remains of Tacy his Wife died
the 7th of January 1773 aged 70 Yrs
Near this place also the remains of Sarah
the wife of JOHN STEPHENS of this
Town Currier, who departed this life the
26th day of December 1779 aged 45 Yrs
Also Mary the 2nd Wife of the last mentioned
John Stephens who departed this life on the 29th day of
March 1800 aged 53 Yrs
Also the above John Stephens Currier who departed
this Life 15th of February 1802 aged 66 Yrs

The burials can be found in the Mitchedean register on the FOD site.

I have summarised much of this data at

http://graememoad.com/Family4/PS78/PS78_248.HTM

(needs to be updated for the burial info)

I am interested in finding more on this family, e.g., surnames of the wives mentioned.