Brightly Shining by Ingild Rishoi

The setting is Oslo at Christmastime.  Two sisters, Melissa and Ronja, live with their alcholic father, who has a hard time keeping a job. Ronja hears about a job selling Christmas trees and encourages him to go for it. He gets the job and life gets better for the little family. But then father falls off the wagon and gets fired. So Melissa,who can see how desperately the family needs income, talks her way into taking over her father's job--though for less money and worse hours. Ronja gets tired of coming home to an empty apartment every day, so she goes to hang out at the tree lot and ends up selling greenery and wreathes, even though she's underage. Then the tree lot owner finds out and all hell breaks loose.

This is really kind of a sad Christmas tale. Though the sisters, particularly Ronja, find adults who help them, their father's drinking has made their future very unstable. The tale finishes with a very cryptic ending. Some people think it represents hope and optimism but others (like me) recall how the sisters kept talking about The Little Match Girl story and think the ending is intended to be sad. You must read it and decide for yourself.