Thank You for the link.
Yes I have seen this before but because I was not sure that Peterston was the shorter name for Peterston Super Ely, I have not done anyhting with it. Edith always maintains in census forms that she was born in Llanharen I thought that Peterston was in that parish but it not.
Birth cert. has birth in Peterston in sub dist. Maesteg in district of Bridgend.
Peterston is next to St George which is also the place name on the old Denbigh/Flints border (birthplace for her mother). I am quite sure that she was not born in N Wales, and to make that long journey (alone?) to have her first baby, then there must be a family connection.
Mary's father was Robert Roberts, Occ=Smith, deceased. (details from Mar. Cert of 1871.)
Perhaps a 1851 census check of Peterston/St George may reveal something. Something for the winter months.