the marriage certificate would give you the fathers of Edward & Mary
Mary Hopson dec qtr 1947 Narberth vol 8c pg 873 to Edward Evans
possible birth reg
Mary Hopson jan qtr 1926 Newcastle Emlyn vol 11b pg 22 mmn Jones
Possible 1911 census for parents of Mary
https://www.familysearch.org/ark:/61903/1:1:X7J2-F8Xbirth regs for possible siblings
Richard Hopson june qtr 1906 Llandovery mmn Jones baptised Gorslas 10 May 1906 son of Thomas (traveller) & Mary Ann Hobson
Susannah Hopson dec qtr 1907 Llandilofawr mmn Jones death reg same quarter Newcastle Emlyn
Sarah Jane Hopson sept qtr 1909 Aberystwyth mmn Jones death reg same qtr Tregaron baptised Llanbadarn fawr 24 July 1909 daughter of Thomas, travelling hawker, & Mary Anne Hobson burial Ystrad Meurig 22 Sept 1909 age 10 weeks address travelling van on the road
Sarah Hopson dec qtr 1911 Carmarthen mmn Jones death reg same quarter Carmarthen
Mary L Hopson dec qtr 1912 Carmarthen mmn Jones
John Hopson march qtr 1914 Newcastle Emlyn mmn Jones
Annie Hopson sept qtr 1915 Newcastle Emlyn mmn Jones
Jane Hopson march qtr 1917 Newcastle Emlyn mmn Jones baptised Llanerchaeron 30 Jan 1919 daughter of Thomas, travelling hawker, and Mary Ann Hopson
Thomas Hopson june qtr 1918 Lampeter mmn Jones baptised Llandissilio 1 July 1918 son of Thomas, hawker, and Mary Ann Hobson
Johnny Hopson june qtr 1919 Newcastle Emlyn mmn Jones