Hi Brenda,
Very sorry to hear about your illness, I wish you the best of health.
The Peterborough, I have been talking about, is in Northamptonshire, not Scotland. It is quite sad that Mary Louise Dunnett, lost both her parents by the age of 16.
Do you have the name of the second witness on her marriage cert? As I said, this might prove to be a useful clue, as it would be nice to confirm that we have found the correct Mary/Maria.
Regards, Kath