Hi,
The family name seems to be Purves, although obviously spellings can vary.
This early the only way to search is Scotlands People, the original records usually give a place where the couple are living.
There was a Helen Purves baptised in Dunbar in 1735, no other children seem to have been recorded.
William Purves and Isobel Gilly would seem unlikely, as this William was baptised in 1717, which would make William very young to be a father in 1735.
There seem to be a number of Purves families in the area, so you may need to build trees for them.
1735 is getting early, and it was a turbulent time so might be difficult.
