This is all I have on them.
1770, Jan 13. Alexr Gray Gardener in Fordyce and Jean Bogie in Banff were contracted. [Banff Parish Register]
Janry 14th 1770. Alexander Gray in this parish contracted with Jean Boggie in Banff and were married. [Fordyce Parish Register]
Therefore when their banns were called, he lived in the parish of Fordyce and she lived in Banff. It is said that she was a lady's maid at Forglen House, and that she was the daughter of James Bog(g)ie of Towie near Cullen.
There are three children in the surviving records, all baptised in Fordyce: Mary 1771, William 1774, and May 1779. There could be others whose baptism records have not survived, but if there were, then either they died before 1855 or they left Scotland.