The Hacon family were long established in Norfolk and Suffolk, I believe they were Danes originally, for instance, the Lord of the Manor of Swaffham was a Dane named Hacon. But I think there is also a connection with Lincolnshire in the mid medieval period.
I'm not sure whether the Isaac Hacon who married Ann Bayes is the same man who married Sarah Bayes some years later. It's not impossible, though, of course it could be his son. Ann was buried at Ashby by Loddon in 1761, so Isaac could have remarried in 1764 to Sarah. Ann was the daughter of Thomas and Ann Bayes, she had a brother named Thomas, living in Salhouse. Isaac was 'of Acle' when they married in 1748. When I was visiting the Norfolk & Norwich FHS Library I was given the advice that Isaac and Sarah's allowed move and settlement from Acle to the parish of Salhouse meant that he was probably a key worker and that I should research the local lord of the manor for estate records.
At Acle there are burial records for Isaac Hacon died 1805 and his widow Elizabeth who died in 1807, so did he marry for a third time, or was this his son?
I wish more Norfolk parish information was online as I can't get up to Norfolk to do research. I did find a little info in the Society of Genealogists holdings: I found Isaac Haykin (brn c1725) with wife Ann at Ashby. This is Ashby by Loddon where Quaker Hacons lived, and the earliest Hacon baptism I have recorded is in 1620 of Robert, son of Robert and Rebecca. They have links too with Norwich and Sco Ruston. It seems that there were three Hacon brothers Robert, William and George. Possibly the sons of Edward who was an inhabitant of the village in 1603. As a note to that, the first name 'Edward' isn't used at all by other Hacon families in Norfolk.
I own a document dated 1725 which shows a connection between the Ashby family and cousins (I assume) in Roughton, Yelverton, and thence back to Gawdy Hacon (and his wife Bridget Gosling) at Topcroft, whose line goes back in that parish to c1491.
Our Sarah Hacon married Henry Liffen in 1791. Her sister Mary married Samuel Barber (or Barker) in 1786 and I believe she remarried in 1817 to John Rix at Upton. The other sister Ann married Peter Browne in 1796 but I find no more references to them....they may have moved away or she died. Browne is too common a name to be sure of anyone. Sarah Liffen died in 1852 at Old Catton by Norwich where she lived with her daughter Sarah Lambert (wife of Edward) and her granddaughter Mary Anne Liffen.
My ancestor is Sarah's younger brother John who moved to London and married there in 1826.
Have you researched the Liffen line at all?