In Part II of “The Storm,” Chopin gives this description of Calixta:  “She was a little fuller of figure that she was five years before when she married; but she had lost nothing of her vivacity.”  Here, it clearly states that Calixta and Bobint have been married for five years.  Five years is a significant number – she and Bobint have a four-year-old son, Bibi, which means that for four of the past five years Calixta has had the responsibilities of both a wife and a mother, and when we first meet her she is sewing furiously, intent on her work.  Five years is long enough for the newness, for the excitement, of her marriage and of her motherhood to wane, yet not so long so as to have buried her own passions.  And so it does not come as a shock to the reader when her old infatuation with Alcée comes to the forefront when they are alone together during the storm.