Paul Frecker's note for this image follows. "This is possibly Lady Mary Codrington, wife of General Sir William John Codrington (1804-1884). From 1859 to 1865, her husband was Governor of Gibraltar. From 1856 to 1885 Lady Codrington was a Bedchamber Woman to the Queen.
Alternatively, this might the first wife of Admiral Sir Henry John Codrington (1808-1877), or the wife of Charles Codrington, Bart.
A fourth possiblity is Lady Georgina Charlotte Anne Codrington (1817-1884), daughter of the 7th Duke of Beaufort and wife of Christopher William Codrington M.P."
From Paul Frecker; image detail-enhanced and sepia tone removed (and replaced in the border only with Photoshop) by gogm.