The portrayal of Mdme. Loisel as "the daughter of the people" can be found early in the short story "The Necklace", where deMaupassant describes in detail the background from which Loisel comes from. In this description, the author emphasizes on the simple nature of her status; that Mathilde does not come from money, has no dowry, and no social status. Yet, the tragic flaw in Mdme. Loisel is that she does not take these things for granted; she does feel that she belongs somewhere else and, for this reason, she is extremely unhappy.
She was simple since she could not be adorned; but she was unhappy as though kept out of her own class; for women have no caste and no descent, their beauty, their grace, and their charm serving them instead of birth and fortune.
Furthermore, he continues to describe woman of the same class as Mdme. Loisel, who may not be as uncommon as we may perceive; theirs is a race of woman born to be princesses, but set to be paupers by the inconveniences of money and social ranking. The author explains that they do exist; that, even though they may not have what it takes to be a "lady", these "daughters of the people", or women of the common folk, are born ladylike, despite of having no title, lineage, nor power.
Their native keenness, their instinctive elegance, their flexibility of mind, are their only hierarchy; and these make the daughters of the people the equals of the most lofty dames.
Therefore, Madame Loisel would be a daughter of the people precisely because she comes from the common folk; she has no wealth to claim, and she is part of the ranks of the working classes, which is a class bracket that constitutes the majority of the people of France at the time the story is set.