Lost Roses by Martha Hall Kelly

At the close of the 19th century,  Eliza Ferriday, a member of a wealthy, philanthropic New York family became a good friend of Sofya Streshnayva, cousin of the Russian czar when both families spent "the season" in Paris.  In 1914, Europe appears to be on the brink of war so these good friends retreat to their individual countries early.  The "War to end all Wars" and the Russian Revolution throw both families into turmoil.  Their stories continue through 1919 when both women find their way back to Paris: Eliza in search of Sofya and other white Russians escaping persecution and Sofya trying to locate her lost son.  Watching all of this is Eliza's daughter Caroline whose story of following the family tradition is shared in Lilac Girls.  Both novels reveal what can happen when strong, determined women are faced with the challenges of a troubled world.  As in Lilac Girls, the main characters are based on real people whose real stories are hard to believe are not fiction.