I assume this is an assignment that is asking you to imagine a scenario in the future, since this conversation never really did take place in the story.
If I had assigned this to my class, I would want them to keep several things in mind. First, the characters should remain true to themselves to at least some extent, because people don’t typically change a whole lot. I would look for Roger to be expressing some sort of thanks, like he wanted to at the end of the story but never did. I would think that Roger would say something about how the experience changed him in a significant way.
I would expect Mrs. Jones to remain true to her character and speak in an uneducated but concerned and helpful manner. Maybe she would say something about why she gave him the money.