How did Helena Citronova survive Auschwitz?

Helena Citronova was taken to Auschwitz in 1942. There was a place in the camp where belongings of prisoners were sorted. The women who worked there had privileges others did not and a better chance of surviving. When a woman that Helena knew worked in Canada died, Helena took her uniform and took her place. When Helena was caught, another SS guard asked if anyone would sing a song. Helena took the chance and sang. The guard, Franz Wunsch was captivated by her. He told her he loved her and tried to establish a relationship with her. When he saved her sister from a crematorium, they began an affair. He kept Helena safe until he had to go to the Russian Front.