The Romanov Heiress. The Lost Romanov Women, #1

Four sisters in hiding. A grand duchess in disguise. An alternate future for the Romanovs. With her parents and brother missing and presumed dead, Grand Duchess Olga Romanova must keep her younger sisters safe. The Bolsheviks are determined to eliminate any remaining holdovers from the tsarist regime, hunting down the last Romanovs and putting them to death. Now living in England, the Romanov sisters remain hidden to protect their identities, even as isolation strains their relationships.
But they can't distance themselves from the world forever. Olga learns that a peer of the realm has accused the late Empress Alexandra of betraying Russia and her allies during the Great War. Under the spell of the scheming Grigori Rasputin, Alexandra disclosed military secrets to the enemy. If this rumor becomes a part of the historical record, it will destroy her mother's reputation and her sisters' futures.
Disguised as "Olivia, " a wartime nurse turned maid, Olga accepts a position in Lord Hammond's household. There, she works to discover the truth about her mother. When Olga meets his lordship's heir-an alluring but enigmatic veteran-her situation grows even more precarious. The more she learns about the tragedies of his past, the more complicated and dangerous their connection, and her own family's legacy, turns out to be.