What comment could I make about "Roman Fever" by Edith Wharton?
Well, I guess a lot of it depends on what kind of comment you want to make about this excellent short story by Edith Wharton. Do you wish to focus on characters, themes or setting for example? Either of these elements will provide you with ample material to make a "comment," as you put it. For example, if you consider the relationship between the two women and the conflict that emerges as the story progresses, you should be able to make a comment on the theme of friendship and how it is presented in the novel.
Note how the two women are presented as childhood friends. Yet it is clear that they don't actually know each other very well, and actually, simmering beneath this longstanding "friendship," lies years of pent up resentment, anger and jealousy. Note what the narrator tells us about Mrs. Slade as she imagines the success of her friend's daughter's marriage and the easy and secure future of her friend:
Mrs. Slade broke off this prophetic flight with a recoil of self-disgust. There was no one of whom she had less right to think unkindly than of Grace Ansley. Would she never cure herself of envying her? Perhaps she had begun too long ago.
Note how this "friendship" then is actually built on solid blocks of hidden resentment, envy and jealousy, which of course all comes out as they survey the "great accumulated wreckage of passion and splendour" at their feet. This would be one possible comment you could make, but you also might want to think about setting and how that ties in with the characters and themes of this great short story.