Work your Magic DragonT!!
Hi Mike,
Magic not working today! There is a suggestion below but it is based on Catherine's mother's name in the baptismal record being wrong! Given the various spellings of the surname Jarman/ Jerman/ German etc, together with the use of patronymic surnames, there is plenty of room for error!
If your Thomas Jarman is the son of William Jarman and Mary - born 14 Oct Pen-y-graig, Aberffraw, baptised 13 Dec 1830 - non-conformist record from Rhosmeirch Independent, Llangefni, it seems he was married as the patronymic Thomas Williams. (As was the case with his brother William Williams/Jerman in an earlier post of yours
http://www.rootschat.com/forum/index.php?topic=707927.0).
Thomas Williams,29, labourer, Llangadwaladr, son of William Jarman married Elizabeth Williams, 24, Aberffraw, dau. of John Williams, labourer on 4 May 1860 at the parish church Aberffraw.
I'm suggesting they were the parents of Catherine baptised 7 Oct 1860 at Aberffraw despite her mother's name being recorded as Margaret.
For all censuses after the marriage the family were recorded with surname Wiilliams at various addresses in Llangadwaladr:
1861 - RG09, 4347, 94, 21 - Thomas 30, Elizabeth 25, Catharine 7 months.
1871 - RG10, 5725, 83,10 - new child William 3, b. Trefdraeth
1881 - RG11, 5573, 59, 5 - new children Thomas 6 & John 2 b. Llangadwaladr
1891 - RG12, 4664, 65, 9
1901 - RG13, 5276, 119,1
William's birth was registered as born 1 Mar 1868, at Trefdraeth, the son of Thomas
Jerman & Elizabeth Williams while Thomas (19 Oct 1874, Llangadwaladr) and John (12 Jul 1878, Llangadwaladr) were registered as the sons of Thomas
Williams and Elizabeth Williams.
Elizabeth Williams died 24 Jan 1906 at Ty Newydd, Llangadwaladr, aged 66, the wife of labourer Thomas Williams. The informant was John Williams, son.
There was also a death of a William son of agricultural labourer Thomas Jarman at Bodewen, Llangadwaladr on 4 Feb 1867. His age was given as 18 months.
I can't find the birth registration for William (b.~1865) nor for Catherine, and I also haven't found baptisms for any child after Catherine.
Does any of this seem likely to you?
Regards