Mathilde changes greatly throughout the course of the story. The story starts with her as being a materialistic, rather high-maintenance woman who desires parties, jewelry, notoriety and a life of comfort and ease. She is bitter and resentful that she doesn't have money, and that she doesn't have servants, a nice house, nice clothes, nice jewelry, or nice parties and friends to be with. She resents the very food she eats, because it isn't good enough for her. She constantly longs for better things, at least in terms of money. She is willing to take money from her husband, that he had been saving for himself, to have one night of happiness at a party filled with shallow, rich people.
When she goes to the party, she enjoys herself thoroughly, and revels in her acceptance and beauty. It isn't until after she realizes she has lost the necklace, and spent years working hard to get the money, that she changes. She gives up her dreams of wealth and fame, and settles into her life with the common people. She learns to work hard. She learns to accept her life. She learns to work hard and take pride in that work. She changes quite a bit from beginning to end.
I hope that those thoughts helped; good luck!
I'd suggest that Mathilde in "The Necklace" is human-like, a mixture of positive and negative traits. This is a story the interpretation of which reveals as much about the reader as it does the story. Condemning Mathilde is harshly judgemental and shows a simplistic interpretation. Every piece of evidence from before the loss of the necklace that can be used to condemn her can also be used to suggest, say, that she is similar to a frustrated artist.
And though the choosing to not reveal the loss of the necklace is certainly misguided, one can't help but see the honor and nobility in it.
In the short story "The Necklace" Mathilda is a woman who is unhappy at the level of her life and stature. She desires nice things and feels that her husband's profession and her own have deprived her of the things which she should have. Her husband is thrilled when the opportunity arises to take her for a special occasion dinner and party. He just knows that she will be excited to attend.
Mathilda is upset because for her it means she does not have a nice dress to wear or fine jewelry. Her husband buys her a dress. She borrows a necklace from a friend who has money and esteem. The evening is wonderful but when it ends Matilda realizes the necklace is missing. She nor her husband can find it.
Rather than tell her friend the truth, Matilda and her husband scrape together the money to replace the necklace. The next ten years of their life they both have to work extra hard to pay for a necklace that she later learns was a fake.
Mathilda is vain ,proud and materialistic which leads her to having a hard life.
Overall, Mathilde is portrayed as a very positive, admirable character, though she exhibits some tendency to aspire to materialism, and she is soemtimes infatuated by it. She is definitely not negative, for in paragraphs 99–104, Maupassant describes the massive effort that she exerts to help pay the debt. The heroism that the speaker attributes to her suggests that readers, finally, are justified in admiring her. The quality of character that is a first cause of the misfortune, however, is her refusal to accept the reality of her genteel poverty and her desire to use the borrowed necklace to appear prosperous.