Earliest Known Ancestors: and Ann's son, Samuel was baptised in Skendleby, Lincs in 1767. He married in 1789 at Belleau & Aby, Lincs. Descent is via Eleanor Crow (baptised 1790, Aby, m. John Hildred 1808, Belleau & Aby). See Hewson Pedigree for more.
Samuel and Sarah Crow are buried at Belleau and Aby, indicating a birth date for Sarah Cheffings of around 1760/61, however I have found nothing more about Sarah. There is an Elizabeth Cheffings marrying in Belleau and Aby in 1790, possibly Sarah's sister?
A fellow researcher reports a burial of Sar dau of John & Elean Cheffings in 1754, from the Belleau BTs. There is no sign of her baptism. The next child baptised to John & Eleanor Cheffings at Belleau is John (1763) on the IGI. However in the Belleau PRs, there are no children recorded to this couple between Eleanor (1749 - 1750) and Elizabeth (1766). The situation is complicated by there being two John & Eleanors and by some gaps and alterations in the register. Since 'my' Sarah named her first child Eleanor, it is tempting to think that she came from this family.
Samuel Crow is in Aby on the 1851 census, aged 85, birthplace given as Skendleby, which links him to a patron-submitted IGI baptism entry: Samuel Crow 6 April 1766, Skendlely, parents John and Ann.
2. Check for gaps in Belleau PRs & BTs around 1760. If none, try non-conformist records for baptism of Sarah.