« Reply #3 on: Tuesday 31 July 18 14:14 BST (UK) »
as there are no relationships given on the 1841, there's nothing to say that 8 month old Ann is the daughter of John & Ann. As for the father's occupation, you said that the marriage cert gave metal weigher so that doesn't match the gardener either.
I'm pretty sure it's the same family as there aren't many Catherine Reeses around and only one in Penclawdd.
I'm not convinced that it's the same family that baptised Ann 22 Nov 1824 and Mary 29 April 1822 in the parish church though. The family from the census baptised some children in the Congregational Church in Three Crosses.
7 January 1830 David & William, twin sons of John Rees of Penclawdd, Copperman, and Ann his wife
7 Jan 1830 Sarah daughter of same couple
same day Jane, "a bastard child nursed by the above John Rees was also baptised"
You can find these baptisms in the Non-conformist and Non-parochial registers available on FamilySearch and Ancestry.
Given the baptism date in 1830, David & William should be more than 8 in 1841.
Perhaps baby Ann in 1841 is another nurse child?
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