The biggest theme I would look at if I were you would be the role of gender and in particular the position of women in these three brilliant texts. In "Hills Like White Elephants," for example, note how Jig assumes a subordinate position. Although her partner, the anonymous American, is in theory sensitive and caring about her and keeps on repeating she only has to get the abortion if that is what she wants, his very insistence is a form of bullying, and the way that he will not let the subject drop shows that the terms he offers Jig are clear: she either gets the abortion, or she loses him. Women are thus shown in this story to be objects who are to be manipulated and abused as the men choose.
If we consider "The Story of an Hour," it is clear that the position of women is another fascinating theme that is worthy of some consideration. Note the way that the suddenly-liberated Mrs. Mallard talks about her experience of marriage:
There would be no one to live for during those coming years; she would live for herself. There would be no powerful will bending hers in that blind persistence with which men and women believe they have a right to impose a private will upon a fellow-creature. A kind intention or a cruel intention made the act seem no less a crime as she looked upon it in that brief moment of illumination.Even though her husband was not abusive or deliberately nastly, clearly the social position of women at the time of writing this story placed them in a subservient position, where, as the weaker sex, they were not allowed to live their lives for themselves. Finally, if we consider the masterful Trifles, the very title of the play indicates the way in which women were sidelined and patronised by the menfolk. Even though the women and their knowledge of housekeeping is what unlocks the secret of the murder, the men disdain their knowledge and make fun of them throughout the play, indicating the way in which women were looked down upon and disregarded in a patriarchal world.