Have you traced the Hunter side?
It would seem Elizabeth Hunter was possibly a local girl
There is a baptism for an Elizabeth Hunter in 1705 at Aberlady, parents Andrew Hunter and Elizabeth Brokie.
Also with the same parents is an Andrew Hunter baptised 1710.
As an Andrew Hunter is a witness to the childrens' baptisms in 1730 and 1734, this may be Elizabeth's father and/or her brother.
By the way, the surname for Andrew in 1734 is given as 'Mathews' not Mathers - I expect you have also serched under this name. Also try Mather as well as Mathers.
Andrew Hunter and Elizabeth Brokie were married 4.5.1700 at Aberlady.
(The father of this one in 1700 was evidently another Andrew - on familysearch.org transcript from the register).
There are several other later marriages for 'Andrew Hunters' at Aberlady - in 1725;1726;1742.
One of them may have witnesses of his sister Elizabeth, or even her husband George.
I see the kirk records for Aberlady are on Scotlandspeople.
Have you looked through these? - perhaps there may a mention of Banns, or a payment for a marriage.
Have you found George's death? Do you know how old he was and when he was born?