Welcome to Rootschat. The best I can find may be worth a look, I would suggest you do not purchase any records before looking for more evidence .
The 1921 census was taken on 21 June 1921, the marriage below, registered between April & June, may be a possibility.
Also two possible children. However I cannot find Catherine with this surname or the others on the 1921 register, I cannot find the children below later but others may be able to help?
Marriages Jun 1921
George Catherine Isaac Rees Merthyr T. 11a 1183
REES, GWYNNETH EDMUNDS
GRO Reference: 1925 S Quarter in MERTHYR TYDFIL Volume 11A Page 1392
REES, VINCENT HARDIE EDMUNDS
GRO Reference: 1923 M Quarter in MERTHYR TYDFIL Volume 11A Page 1402
Two possible deaths but there others later.
REES, CATHERINE 51
GRO Reference: 1938 M Quarter in SWANSEA Volume 11A Page 1134
REES, CATHERINE 63
GRO Reference: 1950 S Quarter in NEATH Volume 08B Page 376
Colin