Hi Middlesbrough,
Yes you are right, I agree with you about "Father in Law", and I queried that, at the time of seeing the census information. You would expect the information was correct, and it would be Susan's father, but having done research on Susannah's father, William Haines, he was a Cooper bap Much Birch in 1782, his first wife Sarah Essex (Mother to Susannah) died in 1830. William and Sarah had daughters, Eleanor, Susannah, Ann and Lucy.
William then married Mary Watkyns in 1833, they were living at the Old Shop Much Birch in 1841 census, following the trade of Cooper. 1851 census shows them living in Hereford Road aged 70 years.
But interesting to note is that Mary Watkyns came from Wattstown, Monmouth, his daughter Lucy Haines and a George Tudor were witness to Susan's marriage in 1843, she was a Servant in Monmouth and Lucy & George later married and settled in Monmouth. Also other daughter Ann died in Monmouth. So it seems to be that much of the Haines family settled in Monmouth
The marriage certificate of Thomas & Susan in 1843 clearly states William Haines a Cooper, as Susan's Father and William Gwillim as Father of Thomas Gwillim, Labourer. So in that 1851 census in Monmouth, it does show William Gwillim - father-in-law as a Labourer.
So as a result of all of this information, I decided that William Gwillim in their census of 1851 must have been incorrect. Of course I stand to be corrected !! Talk about confusion.
William Haines is later shown in 1861 census was living with his son-in-law William Cooper at the School House, Much Birch, aged 81 years and apparently died in 1862.
I await your further thoughts now. Thanking you for your patience.