Christina MITCHELL 1777-1864 appears to be Ephraim's second wife. His first wife Barbara GUTHRIE (died c1801) bore him 3, possibly 4 children.
re the DONALD connection through Ephraim and Barbara's daughter Margaret.
re descendants from Helen BLACK's eldest brother William.
There are probably two further Generations of the BLACK family recorded, as the forename Ephraim does recur in the Dundonald region of Ayrshire back to 1651.