I think that the inclusion of Franklin's family in the narrative is significant because it triggers the change in Ann that we see come full circle at the end of the story. Prior to Scotty's accident, Ann was consumed with the magnitude of herself. Her life, her world, her family, and her state of being compelled her to make plans and live her life as if there was nothing else nor anyone else in it. Ann is not the type of person who widens her scope of compassion to genuinely include anyone or anything that does not fit into her own appropriation of the world. Scotty's accident throws her world into a fundamental tailspin. Carver's construction of Ann's world as one with perfectly designed interiors and meticulously laid plans is thrown into limbo with both Scotty's accident and the overall helplessness that she feels. It is at this moment where she begins to experience sensations and feeling that she might not have previously explored. This comes in the form of living with constant uncertainty regarding Scotty's condition. Even though she and Howard can afford the finest medical care, they are still unable to ascertain any answers as to Scotty's condition or how to help him. Additionally, Ann is left in a position that is unfamiliar to her in that she needs people not to help her accomplish her own ends, but in order to simply "be." It is here where Ann runs into Franklin's family and understands that their predicament is similar to her own. While there are class, social, and racial barriers that would keep her family different from this family of color whose son is the victim to urban violence, Ann recognizes that she holds more in common with them, at that moment, than anything else. Both she and Howard as well as Franklin's mother and father are struggling with a lack of control over their own children and one in which there is pain and suffering in simply being in the world. It is here where Ann begins to experience change. When she asks the nurse what became of Franklin, it is a moment where she changes. This change is what will drive her character towards the end of the short story, especially highlighted in the her interaction with the baker. Carver might be suggesting that the idea of a "small, good thing" could be the expansion of our own scopes of compassion in both good and bad times, allowing us to hear both our own and others' cries of suffering. Something small, something good like hearing how others suffer and allowing this to wash over us in order to understand our own pain might be the path the Carver suggests is the way to redemption. It is for this reason that I think that the inclusion of this family of color in the story is so very important.
To show that Ann desires to connect with others, even if they seem to have nothing in common. Ann has very little in common with an African-American family...she is (I am assuming) white and upper-middle class. The family is more than likely working class (hamburger wrappers on the table...fast food). Ann tried to connect with the baker, but was unable to. She wanted to, though. I think that is why she felt like she should talk about Scotty with the family. She wants to connect to other people.