Mary Proby (1755-1829) (1755–1829) Parents Mary Russell Baptist Proby Children unknown daughter Mackenzie William Frederick Mackenzie Helen Mackenzie, Lady Mackenzie George Leveson Boucherat Mackenzie unknown daughter Mackenzie William Mackenzie Francis John Mackenzie unknown daughter Mackenzie unknown daughter Mackenzie Frances Mackenzie Mary Elizabeth Frederica Mackenzie Siblings Joshua John Proby Caroline Proby Baptist John Proby Charles Proby Partners Francis Mackenzie, 1st Baron Seaforth