Who is Samantha Taper in Caucasia by Danzy Senna and what is their importance?

Samantha is a young, smart, baton twirling dynamo, and the only black girl attending Birdie's middle school. Birdie would love to reach out to Samantha, but she is afraid of placing her own position in school as risk. Samantha knows and acknowledges that Birdie is black, but she never does so openly... only privately.