"Chrysanthemums" and "A Rose for Emily" offer great opportunities for comparison and contrast. The first step that you should take is brainstorming. What subjects and themes are there in the stories and, since it has to be 5 pages, is there enough material to work with?
Let's look at some brainstorming ideas:
1) Setting: You could write about the settings. One takes place in the South, the other takes place in a closed-off valley in California. Both might have enough material to write about setting if you include not only time and place but economic, political, and social conditions at the time plus the prevailing attitudes of men and women. This might be good.
2) Characters: Both stories contain women who are affected by their environment and people in their lives. You could write about how they think, act. feel, and what other characters think about the women. I would choose this one.
3) Theme: Theme is always great to work with and can be included in your thesis statement.
4) Symbolism: There is great symbolism in both stories. There are Gothic literature conventions, "invisible" watches, Emily being constantly "framed," a closed-off valley, travelling salesman, apples, chrysanthemums (especially), and a rose. Flowers can make interesting comparisons. Does one require a great deal of work to care for them?
5) Tone and style: Both stories offer a wealth of description, various sentence styles and unique diction.
6) Figurative language: Possibly some examples. This might be less attractive to write about.
7) Plot: Next to characterization, this is one of the most expansive topics to write about because it includes all the elements of the story: exposition, rising action, complications, etc. This might be too broad.
I would choose female characterization. Start with how they are described. Then what they do, how they think, and what others think about them. Then write about their diction, etc. This is one of the more manageable topics and should fill 5 pages. Good luck with the assignment!