Working back from Elizabeth in 1881
1861 can't read street address Llanelli RG9/4110 folio 108 pg 22
Jenkin Jenkins head mar 32 hammerman in tin works b. Glamorgan, Margam
Elizabeth wife 28 b. Pembrey
Catherine J dau 7 scholar b. Llanelly
David Morris boarder 26 tinman b. Glam, Aberavon
1871 Nevills Row, Llanelli RG10/5464 folio 133 pg 16
Jenkin Jenkins head mar 43 hammerman b. Margam, Taibach
Elizabeth wife 38 b. Burry Port, Pembrey (that what it says on the census, the transcriber has made it into a non-existent place in Ireland!)
marriage
Elizabeth Griffiths and Jenkin Jenkins june qtr 1854 Llanelly vol 11a pg 751
this looks like Catherine in 1881
6 Church St Draper's Shop RG10/5466 folio 100 pg 1
Thomas Anthony head mar 38 draper b. Kidwelly
Mary wife 27 b. Llanelly
Elizabeth Jane dau 3 b. Llanelly
Catherine Jane Jenkins niece 18 dressmaker b. Llanelly
Elizabeth Morgan niece 18 dressmaker b. Llanelly
Evan Rees boarder 21 draper's assistant b. Kidwelly
Thomas Gravel boarder 19 draper's assistant b. Llangendeirne
Jane Thomas 21 domestic servant b. Kidwelly
It would be nice to think that the Mary here is another daughter of John Griffiths, but I can't see a possible marriage and I suspect she may be a Jenkins. To be sure, you could order the birth certificate for their daughter
Elizabeth Jane Anthony dec qtr 1867 Llanelly vol 11a pg 629
Catherine marries sept qtr 1881 Llanelly vol 11a pg 937 to either Thomas Charles or John Davies, most likely the latter as in 1891
Royal Oak Inn, Bryn, Llanelly RG12/4492 folio 27 pg 48
John Davies head mar 39 publican b. Bryn
Catherine J wife 36 b. Llangennech
David J son 2 months b. Bryn
The unmarried sister Ann has been very useful in tying the sisters together
1861 Pottery Place, Llanelly RG9/4112 folio 39 pg 24
John Griffiths head mar widower 61 shipping agent b. Pembrey
Joanna dau 33 dressmaker b. Pembrey
Ann dau 25 dressmaker b. Pembrey
Mary dau milliner b. Llanelly
1871 3 Pottery Place, Llanelly RG10/5467 folio 109 pg 11
John Griffiths head widower 71
Ann dau 32 dressmaker
Margaret Bevan dau 34 sailor's wife
all born Pembrey
Marriage - Margaret Griffiths march qtr 1871 Llanelly vol 11a pg 715 with John Bevan on the same page. In 1881, they're on RG11/5374 folio 156 pg 16 with 2 daughters Elizabeth J b. 1873 and Margaret A b. 1875
1891 1 Mina St, Llanelly RG12/4494 folio 140 pg 20
Joanna Edwards head widow 65 living on own means
Ann Griffiths visitor 53 dressmaker
both born Pembrey
1881 Mermaid Inn, Biddulph St RG11/5373 folio 69 pg 13
John Edwards head 63 publican b. Glam, Aberavon
Joanna wife 55 b. Pembrey
Mary Jones 17 domestic servant b. Llanelly
1871 Mermaid Inn 1 Biddulph St RG10/5466 folio 31 pg 8
John Edwards head mar 54 hammerman tin works b. Swansea
Johanna wife 44 b. Llanelly
Eliza James 17 domestic servant b. Pembroke
marriage Joanna Griffiths march qtr 1863 Llanelly vol 11a pg 627 with John Edwards on the same page
1901 16 Lloyd St, Llanelly RG13/5088 folio 125 pg 25
Anne Griffiths head single 60 b. Pembrey
Jennie Bevan niece 26 dressmaker b. Llanelly
still can't see any link to the other Griffiths family.