The Alice Network by Kate Quinn

1947. In the chaotic aftermath of World War II, American college girl Charlie St. Clair is pregnant, unmarried, and on the verge of being thrown out of her very proper family. She’s also nursing a desperate hope that her beloved cousin Rose, who disappeared in Nazi-occupied France during the war, might still be alive. So when Charlie’s parents banish her to Europe to have her “little problem” taken care of, Charlie breaks free and heads to London, determined to find out what happened to the cousin she loves like a sister.

1915. A year into the Great War, Eve Gardiner burns to join the fight against the Germans and unexpectedly gets her chance when she’s recruited to work as a spy. Sent into enemy-occupied France, she’s trained by the mesmerizing Lili, code name Alice, the “queen of spies”, who manages a vast network of secret agents right under the enemy’s nose… Read more.