I just don't know for sure what you're after here. "Everyday Use" is a work of fiction. They could act any way that the author wanted them to. As they are, they can't possibly act any way than what they do--it's a story. These people are not real. Art is artificial. It's not supposed to be real. They don't have free will--they're characters in a work of art.
Even if you're asking something like:--"If these people were real, how could they have acted differently?"--you could still punch in anything you want. Wangero could have been an axe murderer. Maggie could run up to Dee when she arrives and jumped into her arms. The answers are limitless. If this is really an assignment you have to do, write in anything you want.
Dee could have understood that her mother and Maggie possess their own kind of dignity and don't need outsiders coming in and telling them how to live. The mother could have not been so flippant and made jokes about her guest's name. Dee could have seen her upbringing as more that just quaint and artistic. Again, the possibilities are endless.