>>282988868
Her past is still a mystery but there have been no hints at her ever being a part of it. When we get a glimpse of teenage Yor it's always with her raising Yuri and the areas they live around look pretty intact.
Maybe they just lived in a small village away from the front so the casualties were minimal. Her parents however were probably some of those casualties either directly or indirectly. Else her speech in this page loses a bit of the impact.

>>282978071
It's a real shame, since she's gotten some material for it and Axeman revealed that Loid heard her talking about how everyone their age suffered as children during the war. And yet for some reason he kept that reveal in a bonus chapter over a main one, so that he's not forced to bring it up in the main story.