What kind thing did Bruno's father do for Maria? How did this make Maria feel conflicted?

Maria was always distinctly uneasy about the move to Auschwitz. Nevertheless, she agreed to go along out of loyalty to Bruno's father Ralf. And it's not hard to see why. Maria's mother once worked as a dressmaker for Bruno's grandmother. When she retired, she gave Maria's mother a small pension. When Maria's mother became seriously ill, Ralf paid for her medical care. Sadly, she subsequently passed away, but even then Ralf continued to support Maria, providing for her mother's funeral expenses and taking Maria into his household to work as a maid.
So one can understand why Maria feels so conflicted. She has every reason to be grateful to Ralf for all that he's done for her and her family. At the same time, she cannot in good conscience support what Ralf is doing at Auschwitz, playing a leading role in the murder of so many men, women, and children. However, she chooses to keep her head down and remain quiet, not just out of loyalty to Ralf, but also out of fear that she could end up in serious trouble if she expresses her true feelings on the subject.

In chapter 6, Bruno laments about his new living situation at Out-With and begs Maria, their family maid, to persuade his father into leaving Out-With immediately. Maria is careful not to reveal her negative feelings regarding Bruno's father's occupation and his choice to act as commandant of the Auschwitz concentration camp. Bruno then calls his father stupid and Maria quickly chastises him for his comments. Maria then proceeds to tell Bruno that his father is a good man and tells him about how his father gave her a job when she was in desperate need of money. Maria also mentions that Bruno's father provided her with a comfortable place to live and also gave her food during her time of need. Maria goes on to tell Bruno that his father also paid for her mother's medical bills and funeral when she passed away out of the kindness of his heart. Overall, Maria appreciates Bruno's father for his benevolence but is upset that he chose to support Hitler and the Nazi regime.