There are a number of examples of personification in "The Necklace." This is a literary technique whereby something that isn't human, such as an animal or an inanimate object, is endowed with human qualities. A particularly useful example in "The Necklace" comes in the description of Mathilde's humble lineage:
She was one of those pretty and charming girls born, as though fate had blundered over her, into a family of artisans.
In this particular excerpt, fate has been personified. Fate does not blunder; only humans can do that. What the author is getting at here is the notion that fate made the mistake of putting Mathilde, a charming, pretty girl, into a lowly family of artisans. What's more, this corresponds to how Mathilde evaluates the conditions of her birth.
For this is a woman who regards herself as being possessed of noble blood. So the fact that she was born into such a humble family is a constant source of humiliation. Mathilde's firm belief that she's destined for better things will lead her to make the fateful decision to wear the titular necklace to the Education Ministry ball.
Then there's the personification used to describe the shabby appearance of the Loisels' cramped apartment:
All these things, of which other women of her class would not even have been aware, tormented and insulted her.
No matter how bad the condition of someone's dwelling place, it cannot torment or insult anyone. But that's precisely how Mathilde feels; it's almost as if she's being attacked by her humble living conditions. Again, she thinks she's born to better things and so is aware of her domestic environment in a way that other women of her class would not be.