I've just found that Gorton cemetery records are on Ancestry.
I had googled the name of the cemetery and found their own search facility but, without a subscription, it only told me the names of the dec'd. Everything clear as day on Ancestry! Had I seen that, hopefully I would have realised that Pamela b 1880 and Harry b 1959 were not going to be siblings!
Perhaps we should be telling the Bibby tree owner that the Martha they want probably isn't the one from Clitheroe, but might be this one, even though she is apparently too young. Her mother is the Pamela who is in Gorton Cemetery!
Births Mar 1907
HOLDEN Martha Rochdale 8e 72