The Last Time I Saw Paris by Lynn Sheene
Ex-Okie farm girl becomes Manhattan socialite and leaves her rich husband for Paris, just as the Nazi's occupy the city. She is befriended by a florist, recruited by the Resistance, and becomes the sole support of 2 young Jewish girls in hiding. As expected, she attaches herself to a German officer for the purpose of gaining information. It doesn't end well for her friends, but the girls escape, the true love of her life, survives Nazi imprisonment, and she lives happily ever after running the flower shop. There are no surprises here.