Emily is the oldest daughter in the short story, I Stand Here Ironing by Tillie Olsen. Life has been hard on her mother who, only nineteen herself, was left with Emily to care for when Emily's father decided to leave and "wrote in his good-bye note" that he could no longer cope with their life of "want." The mother relates how she was unable to enjoy Emily's younger years due to work demands and only when she remarries do things improve "and I think perhaps it was a better time."
However, when Emily is five, Susan is born and Emily is already coming down with a fever which will culminate in Measles. Her first associations with Susan are all negative as she is not allowed near the baby and is sent away to convalesce for an extended period. The reader can sense the developing relationship already and, for Emily who already has a compromised relationship with her mother, Susan will become symbolic of a difficult time for her, in a place where "They don't like you to love anybody here." and where "There never was a star"- indicative of Emily's failure to thrive.
The mother is aware of "that poisonous feeling between them, that terrible balancing of hurts and needs." The mother's inadequacies cannot stop the "corroding resentment" and the reader can recognize how the mother must have compared the sisters with Susan being favored as she is "everything in appearance and manner Emily was not." Susan repeats Emily's jokes and is applauded whilst Emily "sat silent,' telling her mother later but the mother not doing anything about it.
All of this supports the theme of sibling rivalry and how, unchecked, it may develop into a bitter separation and cause a rift too large to repair as adults, especially in Emily's case, who is already battling the unresolved issues in her bond with her mother.