Gill
Thanks again. It had occurred to me that they might not have married in England or Wales, but I'm not sure about asking Southport. I used the fiche of the St Catherines Index that the LDS has, and there was no sign of a marriage involving an Edith Louisa Williams from 1920 to 1950 - at which time she would have been 44 or 45. Quite a few involving a John Davies, but no corresponding entry for her.
Given that she was born and died in Bangor I'd have thought that she'd have married there, but people were moving around a lot more then, so entirely possible that she didn't. Richard Williams, her father, died in 1913 so she might well have moved away. Any more ideas would be more than welcome. Thanks again!!!