Nina and Xenia, the two daughters of Grand Duke George Mikhailovich and Grand Duchess George née Princess Marie of Greece and Denmark, painted in London in 1915. The brushwork of the hair, especially, is exquisite. *** Princess Marie and Grand Duke George, probably at the time of their engagement. Princess Marie of Greece and Denmark (3 March 1876, Athens - 14 December 1940, Athens), was the fifth child and second daughter of George I, King of the Hellenes, and Queen Olga, née Grand Duchess…