Williams Family Tree

There is one Caroline Jones living with a David William Jones in 1911 according to findmypast:
Household JONES, Caroline 1903 8 F Merthyr Tydfil Glamorganshire
Indeed, she's the only Caroline Jones in Vaynor in 1911. So these are the people living with her:
Household JONES, David William 1905 6 M Merthyr Tydfil Glamorganshire VIEW VIEW
Household JONES, John 1907 4 M Merthyr Tydfil Glamorganshire VIEW VIEW
Household JONES, Joseph 1904 7 M Merthyr Tydfil Glamorganshire VIEW VIEW
Household JONES, Sarah 1871 40 F Merthyr Tydfil Glamorganshire VIEW VIEW
Household JONES, Thomas 1867 44 M Merthyr Tydfil Glamorganshire VIEW VIEW
Household JONES, Thomas Gwyn 1909 2 M Merthyr Tydfil Glamorganshire

Further prodding with FMP proves that the 1911 census says David William, John, Joseph and Thomas Gwyn are sons of Thomas Jones, Caroline is his daughter, and Sarah his wife.

Margaret leaves the shop to "my nephew David William Jones 25 Holford Street", but this DWJ born in 1905 was, in fact, the son of her nephew. Can one have a grand-nephew? The will of Mary Ann (Polly) Jones mentions "My nephew David Jones, 73 High Street Cefn Coed". This could be the same David William Jones, who actually _is_ the nephew of Mary Ann Jones, although the two wills, written about the same time, disagree on the address.

So it looks like Thomas Jones married Sarah between 1901 and 1903, and David William Jones was his son, aged 20 when Margaret Williams (latterly Thomas) made her will in 1925. A prime candidate for Dai the Rising!