Extract from my original post:- I have checked all the ‘usual avenues’ to try and locate her; electoral rolls, wills, newspapers for obits (including her parents), accounts of funerals and weddings, travel manifests, and the 1939 Registration for Identification Card, but have found nothing of ‘my Gertrude’. Yes, there are several members on ancestry with her photo -- all of which were originally supplied by ME.
The informant on both their death certs, was their son Herbert Browning of 19 Twickenham Road, Leytonstone; he was also the Executor (occupation: Insurance Agent) on both their Wills at this address. There is a very comprehensive account of him in British Army WW1 Service Records 1914-1920 (born 12/4/1885), his last address on this record being this also. However this was not his address at the time of his death (12/11/1956). Noting also (re my initial post), my father Lennox Gordon Hall (Gertrude's son) was in Herbert's care at some time (unknown where & when).