How is Edna an outsider at Grand Isle?

Edna is an outsider at Grand Isle because unlike the other guests, she is not a member of the Creole community despite her marriage to a Creole man. In Chapter IV, Edna notes that Creole women seem freer about intimate issues than she is used to, while at the same time maintaining a “lofty chastity” or fidelity and purity. Edna’s discomfort around this duality leads Adèle Ratignolle to warn Robert that Edna might take his flirtations seriously.

Why does Robert Lebrun leave for Mexico?

Officially, Robert Lebrun leaves for Mexico because he hears about a business opportunity there, and he wants to earn more money. However, we later learn that he departs suddenly because of his growing feelings for Edna. Robert doesn’t think Edna feels the same way about him. In addition, he doesn’t want to break up Edna's marriage, as we see from his hesitancy to begin an affair with her even when she confesses her feelings.

Is Edna in love with Alcée Arobin? 

Edna is not in love with Alcée Arobin, but he allows her to explore her newfound sensuality. At the end of Chapter XXV, when Alcée begs Edna to continue their friendship, Edna realizes that even though she feels nothing for Alcée, she enjoys how his romantic attention makes her feel. In the aftermath of their first kiss, Edna regrets her first experience of the excitement of desire had no love in it.

Why does Adèle Ratignolle stop visiting Edna in New Orleans?

Adèle stops visiting Edna because of Edna’s association with Alcée Arobin. Arobin’s habit of seducing married women is so notorious in New Orleans society that Doctor Mandelet identifies Edna having an affair with him as a worst-case scenario, highlighting Alcée’s ability to damage other reputations by association. In the eyes of society, Edna’s time alone with Alcée brands her as immoral. Therefore, Adèle can no longer keep Edna’s company without facing social consequences.

Why does Edna move into the “pigeon house”?

Edna moves into the pigeon house as an expression of her autonomy and independence. Because Mr. Pontellier’s money funds their married lifestyle, Edna realizes that she cannot fully express her autonomy in their home because she is beholden to his wishes there. Edna pays for the small house with her own money and employs only a few servants with whom she feels close, which means she can truly be the mistress of her own house.