One of the main themes in this short story was trust. In the beginning, Roger had done nothing to let Mrs. Jones trust him, in fact he had tried to steal from her, but when the pair reach Mrs. Jones house, she leaves the door open, because she trusts that he won't try to run away.
Forgiveness was also another main theme in the story "Thank You, Ma'am". Mrs. Jones learned to forgive Roger even though he tried to steal her purse.
In 'Thank You, Ma'am", Mrs. Jones gave Roger his dignity. by not embarrassing by asking hi questions, but instead, shared her story. At first, Mrs. Jones really looked down on Roger, but after getting to know him, she starts to warm up to him.
Another major theme throughout the book was generosity. Mrs. Jones wasn't rich, in fact, she was relatively poor. She worked late at a hotel spa, and she also lives with multiple people, which shows that the $10 she gave Roger was quite a sacrifice.