Mathilde is highly dissatisfied with her life. She is “pretty and charming,” but she is poor, and she resents it greatly. With no dowry, she cannot climb up the social ladder and must marry a “minor official at the Ministry of Education.” Clearly, Mathilde doesn't really love her husband, for she “let herself be married,” and this sounds more like she has resigned herself to something she would rather not do and has little enthusiasm for.
Mathilde also tends to feel very sorry for herself. Instead of making the best of her situation, for she is much better off than many people, she sighs and mopes that she cannot have fancy clothing or a beautiful house or rich foods or all sorts of luxuries. Again, she becomes greatly resentful as she looks around her home and does not see the wonderful riches she wants. Mathilde, then, is really something of a spoiled brat. She doesn't get her way, so she pouts. Then when she spends time with a rich friend, she comes home and cries for days with “sorrow, regret, despair and misery.” Mathilde simply cannot appreciate the good things she has, for she always wants more.
Mathilde's husband does his best to please her. One day he even brings home an invitation to a fancy party, thinking that Mathilde would be thrilled. She is not. She is actually angry and impatient because she has nothing to wear. Then she starts to cry until her husband (with a gulp) tells her she can get a new dress. Mathilde may not actually be trying to be manipulative, but she is. Even the new dress does not satisfy her, for she has no jewels to wear with it. Her husband tells her to borrow some from her friend.
Finally, Mathilde seems to find some joy, or at least some pleasure, but it is short lived. She has a marvelous time at the party, but the night ends in horror as somehow Mathilde loses her friend's “diamond” necklace.
The purchase of a replacement sends Mathilde and her husband into true poverty, but surprisingly, this actually improves Mathilde's character. She is set on paying off the debt, and she works hard for ten full years until the couple pays back every last penny. Mathilde is strong now. She is much less focused on her appearance and surroundings. She does what she must do without complaint or resentment. She has become proud of her hard work and of the fact that she and her husband have paid their debt.