Is this the family in 1861:
Address: Griddleton Road Stanton St Quinton Wiltshire
Robert Smith Head M 58 Stanton St Quintin, Wiltshire occ: Ag Lab
Elizabeth Smith Wife F 42 Corsham, Wiltshire
Edwin Smith Son M 17 Stanton St Quintin, Wiltshire
Francis Smith Son M 15 Stanton St Quintin, Wiltshire
Caroline Smith Daughter F 5 Stanton St Quintin, Wiltshire
if so Elizabeth's birth place is recorded as Corsham Wiltshire
possible baptism:
Name: Elizabeth Tanner
Residence Place: Corsham, Wiltshire, England
Christening Date: 19 Oct 1817
Christening Place: Corsham, Wiltshire, England
Father's Name : Joseph Tanner
Mother's Name: Betty Tanner
possible sister:
Name: Caroline Tanner
Residence Place: Corsham, Wiltshire, England
Christening Date:30 Apr 1820
Christening Place:Corsham, Wiltshire, England
Father's Name: Joseph Tanner
Mother's Name: Betty Tanner
Edit: In the 1851 census Elizabeth's birth place is recorded as Marshfield Gloucestershire
Possible marriage for her parents:
Place: Grittleton Wiltshire
Church name: St Mary the Virgin
Marriage date 20 Feb 1809
Groom name: Joseph Tanner
Grooms parish: Marshfield
Bride name: Elizth Jones