It would have been helpful, if you want details of Sarah, to have given her surname as shown on the 1800 marriage entry, YEAT.
That St John Wagstaff had a middle name of LIVESEY is also relevant, given the 1760 marriage of Richard Wagstaff and Jane Livesey in Puddington. There's a baptism on the IGI (extracted so reliable) of Richard Wagstaff, son of Richard and Jane, at Podington on 19 July 1767.
All the above is available free on the IGI at
www.familysearch.orgThere are burials in Podington of Richard Wagstaffs on 29 Apr 1793 and on 25 Feb 1823 aged 56 which fits pretty neatly with the 1767 baptism. Sarah Wagstaff age 61 was buried at Podington on 16 July 1826. I can't see a baptism for her in Beds, but perhaps she was from Northants which is within spitting distance of Podington. You need to check the marriage entry to see if a parish of residence other than Podington is shown for Sarah
David