The Light in Hidden Places by Sharon Cameron
Based on the true story of a Polish teenager who hid 13 Jews in her attic during WWII, this book was fast paced and hard to put down. Catholic Stefania "Fusia" moves from her family farm into town and gets a job with the Diamant family in their shop, and moves into their house. She's considered one of the family and is even secretly engaged to one of the songs (Izio).
Then the Germans invade, and the Diamants are sent to the ghetto leaving Fusia alone. Fusia's mother has been sent to a labor camp, and now she must care for her young sister all alone.
Eventually one of the Diamant sons, Max, escapes the trains headed to the camps, and Fusia and her sister Helena decide to hide him, and others from the Nazis. She risked her life to save 13 others.
This book is based on Stefania's actual memoir, and written with the help of interviews from people who lived through the event, or who knew people who lived through it.
This book is available through OverDrive or on Libby.