Gladys Mary Juliet Herbert of Bulbridge House, Wilton, became Lady Lonsdale in 1878 when she married the 4th Earl of Lonsdale. They had a daughter in 1881, Gladys Mary Juliette. Lonsdale died in 1882. In 1885 she married the Earl de Grey and became the Countess de Grey.
Lady Lonsdale was a professional beauty and a close friend of the actress and society beauty Lillie Langtry. Following her marriage to the Earl de Grey her London address was 14-15 Carlton House Terrace. The Earl also had a country home at Lowther Castle, Penrith, and Whitehaven Castle, Cumberland.
Burke, E., The Peerage and Baronetage of Great Britain and Ireland, London; Debrett's Peerage, Baronetage, Knightage and Companionage, London, 1896; Cumberland and Barnes Post Office Directory, 1859, 1861, 1862; The Mayfair [etc] Post Office Directory, 1886-87, 1887-88; Langtry, Lillie, The Days I Knew, London, 1925.