Just as I was about to go to bed, I had a thought.
I tried Family Search, they have some Lemington Cemetery records (search in the catalogue for England, Northumberland' Lemmington' and they then come up correctly billed as Lemington - I've tried reporting that error numerous times, but it hasn't been corrected)
https://www.familysearch.org/search/catalog/828165?availability=Family%20History%20LibrarySadly they don't have the burial registers for 1930 BUT they have an index for burials that covers 1930 which gives the folio and grave number for the graves register and they also have grave registers :-)
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Index to burials surnames starting with H -dated 1930 showing William Jackson Hall
https://www.familysearch.org/ark:/61903/3:1:3QHV-L3VC-J2GZ?i=586&cat=828165Graves register folio 343, grave 2743 (as given in the index for William)
https://www.familysearch.org/ark:/61903/3:1:3QHV-P3VC-J9HT-1?i=404&cat=828165which shows both William and Marion are buried in the same grave
and they do have the burial register for 1957 for Marion
https://www.familysearch.org/ark:/61903/3:1:3QHV-P3VC-J9H7-8?i=50&cat=828165with the info from Marion's burial date I checked for a death notice for Marion
Newcastle Evening Chronicle
08 July 1957 page 18, col 1
HALL Westerhope 1 Mitford Drive on July 6, aged 88 years Polly dearly loved wife of late William. Interment at Lemington Cemetery on Wednesday at 2.30 pm Will friends please meet at
W** (really blurred, can’t make it out) Whorlton Church for service at 2 pm
(see reply 15)
So the likely death registration I found for William now has the extra verification needed to confirm it :-) and Marion was known to her friends as Polly!
Boo