Sorry I forgot to mention that I found the Probate entry at Ancestry but you could get a copy of his will here, under the "Wills and Probate 1858 – 1996" index,
https://probatesearch.service.gov.uk/#willsThis looks like Ellen in 1938,
UK, City and County Directories 1938
10 Parkhill rd Birkenhead
Mrs Ellen M MARGRIE
I think this is their daughter Ethel's marriage, as Ethel has the name MARGRIE crossed out and replaced with DAVIES in 1939.
Ethel E MARGRIE Sep Q 1942 Birkenhead 8a 1507
James DAVIES
The family seem to have moved to Wembley by 1942 as I can find them in London, England, Electoral Registers.
1948 and 1949 (Margaret ROBBINS isn't there in 1949)
11 Drayton Waye, Wembley
Ethel E DAVIES
James DAVIES
Ellen M MARGRIE
Margaret P M ROBBINS
1950 She is also at her brother and sister -in-law's house.
Transcribed as 62 Sherwood Road, Harrow but on the image it is 62 Roxeth Green Ave,
Ellen M MARGRIE
Dorothy VEALS
Stanley G R VEALS
1951 and 1952 still at 62 Roxteth Ave, Harrow with Stanley and Dorothy VEALS.
1954 and 1955
33 Draycott Avenue. Wembley
Aubrey R W ATKINSON
Valerie A ATKINSON
Ellen M MAGRIE
1956
64 Draycott Avenue, Wembley
Mabel G MACHIN
Ellen M MAGRIE
Nora E RIDGEWELL
1957, 1958 (Nora is now Leonora E), 1959 still Leonora E, and Cecil is not there.
64 Draycott Avenue, Wembley
Cecil F MACHIN
Mabel G MACHIN
Ellen M MAGRIE
Nora E RIDGEWELL
Then I can't see her anymore.
I think the death found by nanny jan is right as Wembley was in Willesden Registration District.
Daisy