Her wrap is in the Murray tartan. The background looks like Scottish countryside. Her article in thepeerage is here.
Upgrade image posted 31 August 2016 from liveinternet.ru/users/4657722/post214372196.
The square neckline and tight sleeves suggest this portrait dates from around the time of her wedding, 1866, or later.
Keywords: Buckner, Gertrude Coke, Gertrude Murray, Countess Gertrude of Dunmore, Coke family, Murray family, Countess, British, straight coiffure, square neckline, modesty piece, long tight sleeves, engageantes, lace, crinoline, floral bodice ornament, neck band, pendant, bracelets, wrap