Annual lists of voters in Glamorgan and subsequently in Birmingham will provide their addresses and will narrow down the date they moved to Birmingham. Few are online however so it will require the old-fashioned approach of visiting county archives and working through hard copy records.

When their daughters reached the age of 21 they will appear on the lists of voters; when they disappear from the lists of voters at the parental home, it is likely that this will indicate their marriage.

I can only find the births of two daughters: Margaret born Q2 1924 and Mary E. born Q3 1925, both born in Pontypridd registration district.

Margaret married Albert T.Clarke in Q3 1947 in Birmingham registration district; Mary E. married Mostyn Richards in Q2 1947 in Birmingham registration district.

There appear to have been the following offspring from these marriages: Robert E. Clarke born Q3 1948, Raymond J.Clarke Q2 1953, and Shirley E.Richards born Q3 1949, all born in Birmingham registration district.

Sarah Beamand died in Birmingham registration district in Q1 1954 age 73; Samuel G.Beamand died Birmingham registration district in Q3 1960 age 72.

I apologise if you have already have all this information.

Good luck with your research!