Williams Family Tree

The John Thomas Williams 1932 inheritance letter says that Margaret Thomas was the sister of JTW's mother, Sarah Williams nee Williams. So it seems she was born Margaret Williams and must have had a husband surnamed Thomas. That's the only evidence for the existence of this chap.

Cannot find Margaret in the 1881 census, despite the fact that Harry Thomas, son, should have been 2 then. But I do find a William R Thomas living at 75 High Street, Cefn Coed. He's a miner married to Thomasine, and they have a son Henry, who's 2. So is Harry/Henry actually Margaret's stepson? That could explain why Margaret didn't leave them anything, and why the children weren't living with them in 1891.

Here's a possible death record for Thomasine:
England & Wales, FreeBMD Death Index: 1837-1915 about Thomasine Thomas
Name: Thomasine Thomas
Estimated birth year: abt 1848
Year of Registration: 1886
Quarter of Registration: Oct-Nov-Dec
Age at Death: 38
District: Merthyr Tydfil
County: Breconshire, Glamorgan, Mid Glamorgan
Volume: 11a
Page: 335

and that age matches William R Thomas's wife in the 1881 census. Here is a possible marriage for Thomasine and William:
Surname First name(s) District Vol Page
Marriages Mar 1868 (>99%)
Dawkins Thomasine Merthyr Tydfil 11a 443
James Ann Merthyr Tydfil 11a 443
Thomas William Merthyr Tydfil 11a 443
Williams Joshua Merthyr Tydfil 11a 443
and Thomasine and William's eldest child was born about 1868, so that matches.

So here is a possible marriage for Margaret and William:
Surname First name(s) District Vol Page
Marriages Sep 1889 (>99%)
Preece Tracy William Merthyr T. 11a 788
Thomas William Richard Merthyr T. 11a 788
Watkins Sarah Elizabeth Merthyr Tydfil 11a 788
WILLIAMS Margaret Merthyr T 11a 788

which matches the long-guessed surname of Sarah, allegedly Margaret's sister.