What are two pieces of evidence from the end of "The Necklace" that show Mathilde is still not a completely mature person?
Despite the turn in her fortunes, Mathilde still dreams of a life of ease and wealth. She remembers how admired she was at the ball years ago, and still yearns for the adoration and regard of others. Essentially, Mathilde still pines for "universal homage and admiration."
But sometimes, when her husband was at the office, she sat down by the window and thought of that evening long ago, of the ball at which she had been so beautiful and so much admired.
Although unhappy with her circumstances, Mathilde shows no regret for the life of penury into which she plunged her husband, a man who "mortgaged the whole remaining years of his existence, risked his signature without even knowing if he could honor it" and who for love of his wife has endured "the prospect of every possible physical privation and moral torture."
The second piece of evidence showing Mathilde has not changed can be found toward the end of the story, when she meets Madame Forestier again after many years.
It was Madame Forestier, still young, still beautiful, still attractive. Madame Loisel was conscious of some emotion. Should she speak to her? Yes, certainly. And now that she had paid, she would tell her all. Why not?
When Mathilde recognizes Madame Forestier, she is "conscious of some emotion." Although the narrator doesn't identify this emotion, we can speculate Mathilde may feel a combination of jealousy and envy. First, Madame Forestier is still young and attractive, while Mathilde no longer is. Second, Madame Forestier is wealthy, while Mathilde's fortunes have taken a turn for the worse.
Notions of class and status are still important to Mathilde, and just like before, she is wary about telling Madame Forestier the truth. She fears how the truth will affect her former friend's impression of her. This time, however, Mathilde believes her pride can finally allow her to unburden herself to Madame Forestier. After all, she feels she acquitted herself well; through seemingly insurmountable odds, she and her husband managed to pay off the balance on the diamond necklace. Here, it can be argued Mathilde has not changed in this aspect of her character; she is still absorbed in superficial notions of refinement and class.