« Reply #7 on: Tuesday 24 July 12 10:23 BST (UK) »
The Lewis Jones of the family posted by Brevitas isn't on any later census as he died before 1851. It also looks like John may have died as there is another younger one.
Tynllecha Ishaf, Cadoxton juxta Neath HO107/2464 folio 336 pg 7
Ann Jones head widow 58
Lewis son 26 tinner in tin works
Ann dau 24
Griffith son 19 washman in tin works
Margaret dau 18
David son 15 washman in tin works
Ebenezer son 11
John son 9
Jenkin son 1
Margaret Davies visitor 2
all born Cadoxton
Lewis was buried 15/8/1849 in Cadoxton parish church, age given as 63, address matches 1841 & 1851 census.
There's another Ann Treharn baptism that's possible 15/6/1794 Neath St Thomas dau of William & Elizabeth
Tthis would seem to be the wrong family for your John unless they had 2 sons called John.
The 1861 for John & Sarah doesn't give their place of birth as Swansea, just Glamorgan. There is no ditto from the person above on the census page who was born in the parish of Swansea.
Reed Fach, Swansea Lower RG9/4107 folio 38 pg 3.
John Jones head mar 35 labourer
Sarah wife 39
Ann dau 8
Mary dau 5
Gwillim son 3
all born Glamorgan
If you don't have Ann's birth certificate, how do you know what her mother's maiden name was?
Cornwall: Allen, Bevan, Bosisto, Carnpezzack, Donithorn, Huddy, James, Retallack, Russell, Vincent, Yeoman
Cards: Thomas (Llanbadarn Fawr)
Glam: Bowler, Cram, Galloway, James, Thomas, Watkins
Lincs: Coupland, Cram
Mon: Cram, Gwyn, John, Philpot, Smart, Watkins
Pembs: Edwards (St. Dogmael's)
Yorks: Airey, Bowler, Elliott, Hare, Hewitt, Kellett, Kemp, Stephenson, Tebb