In Cofer's "American History," what happens when Elena goes to Eugene's house?

In Cofer's "American History," Elena suffers the results of a prejudiced situation when she goes to her friend Eugene's house. First, the mother, not Eugene, meets Elena at the door. After Elena explains that she is Eugene's friend and there to study, the mother responds with the following:

"Listen. Honey. Eugene doesn't want to study with you. He is a smart boy. Doesn't need help. You understand me. I am truly sorry if he told you you could come over. He cannot study with you. It's nothing personal. You understand?"

Eugene's mom rejects Elena's friendship with her son because Elena is Puerto Rican and lives in the tenement apartments next door. The mother tries to overshadow her prejudiced feelings by saying they won't be residing in that house for very long, so there's no need for Elena and Eugene to be friends. She says when they move it will be harder to leave if he has to say goodbye to any friends. 
Elena is shocked and can't move after hearing such prejudiced excuses. Eugene's mother has to ask Elena in an angry tone if she understands before Elena finally snaps out of her amazement and turns to leave. Because of this exchange with Eugene's mother, Elena's hopes of having a friendship with Eugene are dashed. She learns there will always be prejudiced people in the world and to listen to her mother more often. In fact, Elena's mother warned her about going over to Eugene's house right before she went there. It is possible, though, that Elena needed to experience the heartaches she did in order to face the realities of life.