What is the theme of "Ripe Figs" by Kate Chopin?

Another theme of this story is that patience can be taught. Young people can struggle with patience, and this is the case with Babette; older folks tend to have a bit more patience because they have the experience to know that time moves more quickly as we age. This is supported by Maman-Nainaine's assertion that the figs have ripened early and Babette's response that it feels as though they have ripened late. For Babette, then, the time has passed slowly, but for Maman-Nainaine, it has gone by quickly.
In addition, the similes used to describe them help us to really see the difference between the goddaughter and godmother in the story's beginning:

Maman-Naiaine was as patient as the statue of la Madone, and Babette as restless as a hummingbird.

We might imagine Maman-Naiaine as very still and contrasting significantly with Babette who is compared to a hummingbird, something that moves so fast that it can appear blurry to our eyes! However, by the story's end, Babette is able to wait through the entire day that she discovers the ripe figs, until the next morning. She patiently waits until Maman-Naiaine is seated and ready to eat, and then she brings "a dainty porcelain platter, which she set down before her godmother. It contained a dozen purple figs, fringed around with their rich, green leaves." It is in this quiet and still way that she lets her godmother know that the figs are ripe. We see that the lesson has worked and Babette has learned some patience: she did not sprint home from the trees the day before and shout her joy. She was able to delay and present proof of the figs, beautifully arrayed, and this helps to demonstrate her growth.

The theme of "Ripe Figs" is that human maturity is related to the seasons of the year, a process that cannot be hastened.
In Kate Chopin's story, the young character Babette wants to go to Bayou LaFourche to visit her cousins, but Maman Nainaine insists that she wait until the figs ripen. Babette, of course, is impatient and watches the green figs each day, hoping that they will soon change their color so that she can depart:

She walked slowly beneath them, carefully peering between gnarled spreading branches.

Each time she comes out, she is dispirited. Finally, Babette comes to Maman Nainaine and shows her a dozen purple figs on a porcelain platter. Maiman Nainaine exclaims that the figs have ripened so early, but Babette insists that they have ripened late. This is the contrast between youth and maturity: the concept of time is different. Hence, the stipulation that Babette wait until the figs mature. For, watching the figs mature may have encouraged patience.
Then, Maman Nainaine takes her knife to the ripened fig, and as she peels it, she tells Babette to give her love to all her cousins. By forcing Babette to pay attention to the maturation of the fig, Maman Nainaine, perhaps, hopes to teach Babette to follow the pattern she has watched and allow time for things to come about.