I was able to find both the title of the painting on the postcard and a biography of the artist. The painting on the postcard is the work of O.A. Kiprensky and it is entitled "Sibyl of Delph (Portrait of N. S. Semenova)." Orest Adamovich Kiprensky (24 March [O.S. 13 March] 1782-17 October [O.S. 5 October] 1836) was a leading Russian portraitist in the Age of Romanticism. His most familiar work is probably Alexander Pushkin's portrait (1827), which prompted the poet to remark that "the mirror flatters me". The lady in the postcard is Nimfodora Semenova (1788-1876), a Russian actress.
Oil on canvas
110.2 x 109
The A.A. Bakhrushin State Central Theatre Museum, Moscow, Russia
O.A. Kiprensky Wikipedia Entry
Olga's Gallery: Nimfodora Semenova