Who is Emma from Waiting for the Rain and what is their importance?

Emma is one of Tengo's classmates in Johannesburg. She is described as intelligent.... and is at the top pf her class, a position she shares with Tengo. Over the course of the novel, Reverend Gilbert begins tutoring the two, and they quickly become more than study partners. Tengo, however, worries about the progression of their relationship and ends it before things go too far.