Hi Geoff,
Well, that rules out both Mary Martinson's that I found so it looks like back to the drawing board.
I will now update my records with the information you have found, I see she had a brother called William so I bet Swithin has changed his name to his favourite Uncle's - think I would as well!!
Thank you again for the additional information (re marriage & death) and will now see if I can find any more about Mary!
Gill