What motivates Bruno's mother the most?

Bruno's mother is most motivated by her worry for her children and her hatred of her new husband's new post. She isn't happy about their move to Auschwitz, but she conceded because of the position's importance. Bruno's mother is well aware that her husband has no choice but to fulfill Hitler's instructions and accept the post.

“It’s a very important job,” said Mother, hesitating for a moment. “A job that needs a very special man to do it. You can understand that, can’t you?”

“We don’t have the luxury of thinking,” said Mother. “…Some people make all the decisions for us.”

He paused for a moment and looked out the window to his left—the window that led off to a view of the camp on the other side of the fence. “When I think about it, perhaps she is right. Perhaps this is not a place for children.”

"It's horrible …. Just horrible. I can't stand it any more"