His son David Robertson became a minister .
His son David Robertson married Eleanor Charlotte Dalrymple - Fergusson , daughter of Sir Charles Dalrymple Fergusson , 5th Baronet of Kilkerran .
His son David Robertson became a minister and married Eleanor Charlotte Dalrymple - Fergusson , daughter of Sir Charles Dalrymple Fergusson , 5th Baronet of Kilkerran .