About Mary Ogilvie
John Forbes, Esq., captain R.N.; who m. Mary, dau. of Dr. Ogilvie, M.D. of Murtle, a lineal descendant of Sir John Drummond, 1st of Hawthornden, and heiress, by special settlement of her cousin, Mrs Barbara Drummond (who d.s.p. in 1789, wife of Dr. William Abernethy-Drummond, and only dau. and heir of William Drummond, Esq., of Hawthornden), upon which occasion Mr. Forbes assumed the additional surname and arms of Drummond.
SOURCE: Sir Bernard Burke. A genealogical and heraldic dictionary of the peerage and baronetage of the British Empire 31st ed. Published 1869 by Harrison in London. page 363