IF YOU LIKED...
If you read and loved Last Christmas in Paris, then I'd highly recommend Maisie Dobbs, the first in a (new-to-me) mystery series. Both novels take place during The Great War (what we now refer to as WW1), and both are romantic and heartbreaking and full of memorable characters. In Last Christmas in Paris, the story is told in an epistolary style, with letters traded between friends throughout the war. Maisie Dobbs, in her first case since opening her own practice, must confront her memories of the war as she works to help soldiers who have come home with various wounds, both physical and spiritual.
And if you're a fan of historical fiction but haven't read either, I'd highly recommend both novels, as both earned spots on my top ten list in 2017.