Robert Duff, 4th of Drummuir (born 1698) (b. 1698) Parents Catharine Duff Alexander Duff Children Catherine Duff Archibald Duff, 5th of Drummuir Siblings Katherine Duff Janet Duff John Duff James Duff Mary Duff Anne Duff Alexander Duff William Duff, 1st of Muirtown William Duff Partners Isobel Campbell of Clunes