The Christmas Ship (Love's Great War #5)
Linda Andrews

Roselle Perrine works in soup kitchens and her family farm by day, and spies for the Belgian resistance at night. She uses her position in society to convince Jacob to stay in her chateau, hoping the relief delegate's presence will cover her nocturnal activities.
But the Kaiser's Army is watching.
When Roselle's spying is discovered, will Jacob remain neutral or fight for love?