How do Mila, Felicia, Halina, Adam, Bella, and Jakob survive the German occupation of Warsaw in the novel, We Were the Lucky Ones?

Mila, Felicia, Halina, Adam, Bella, and Jakob all live in Warsaw for a time after fleeing Radom, but it is not much safer, as it is also occupied by the Germans. They work various service jobs and pass themselves off as Christian. Mila ultimately leaves Felicia at a Catholic convent on the outskirts of town, believing she will be safer there.