The sitter was Ellen Odette Bischoffsheim (1857 - 1933). She married the 4th Earl of Desart in 1881 as his second wife, and from 1922 was a Senator of the Irish Free State. Ricard was a renowned portraitist who from 1850 regularly exhibited at the Salon. Judging by the age of the sitter, this picture was perhaps painted on the artist's second trip to England in 1870-1871.
The National Gallery, Trafalgar Square, London WC2N 5DN