Twlya is the main character, and the stories narrator. I think that I would describe her as determined, and a bit hard headed. She gets into conflicts (such as the busing one and of course her interactions with Roberta) and she is very hard on herself.
I would have to say that Twyla is a girl that was brought up by her mother--to be same what racists, but at the same time she is a strong girl and improves that aspect of her. For example, at begging of the story she refers to Roberta (the African American) as being "smelly," however she only said this (I think) because of what her mother told her, "that they never washed their hair and that they smelled funny." Nonetheless, as the story progressed and she continued to narrate her life story, she runs into Roberta, but this time the one that gets mistreated or alienated is her. Although, it was twelve-years after the orphanage, the level of racism was not the same--blacks and whites were already interacting with each other. She wanted to be friends with Roberta, but for some odd reason Roberta made this impossible through out the end of the story.