Birthplace of Margaret Mccully

I have traced back my McCully ancestors to Margaret McCully and her 3 sons, John, Ephraim and Edward.

They arrived in Charleston, S.C. in November of 1772 on a ship that sailed from Belfast, Ireland.

I am descended from Ephraim McCully through his son, Hillary.

As far as I know, there was no country of birth listed for Margaret or her sons on the ship's
manifest. I would also like to know what Margaret's husband's name was, if at all possible.