1851 census confirms what you have said and that sarah is 56 and born Wilsford, Wiltshire, England (and they lived at All Cannings, where my bunch come from :-)
I'd think most likley is George Frankilin married
familysearch.org has a few children
link
https://www.familysearch.org/search/records/results#count=20&query=%2Bsurname%3Afranklin~%20%2Bbirth_place%3A%22all%20cannings%2C%20wiltshire%22~%20%2Bbirth_year%3A1822-1850~%20%2Bfather_givenname%3Ageorge~%20%2Bfather_surname%3Afranklin~%20%2Bmother_givenname%3Asarah~
One thing that would be worth a mention is that Beckhampton falls within the parish of Avebury
In which case the nearest one I can see is
10 Jun 1798
Forenames:George
Surname:FRANKLIN
Fathers forenames:Thomas
Mothers forenames:Bythia
Place:Avebury
Hope this helps
Peterson