We see the first internal conflict in Guy de Maupassant's short story "The Necklace" detailed in the very first paragraph. The protagonist Mathilde Loisel is described as a very "pretty and charming" girl born into a working-class family and who was eventually "married off to a little clerk in the Ministry of Education." Yet, because she was beautiful, graceful, witty, and charming, she internally felt as though she compared with a lady of high class and was therefore as miserable in her marriage as if she had "married beneath" her own class. In other words, Mathilde felt thwarted by her own social standing and as if she deserved better, which was of course impossible for her to achieve because it's very difficult to rise from a lower class to a higher class. Hence, the first internal conflict can be described as the desires of self vs. social circumstances.
A second internal conflict can be described as vanity vs. circumstances. When her husband shows her an invitation to a formal event, he thinks she will be thrilled, but instead she cries because she thinks she doesn't have a suitable dress to wear. When she gets her dress for 400 francs, she's sad again because she has no jewels to wear with it, saying, "There's nothing so humiliating as looking poor in the middle of a lot of rich women." What she doesn't realize is that it's presence of mind that makes a person look poor vs. rich. If she shows up with self-possession, poise, and elegance, what she's wearing will hardly be of significance to her viewers. Hence, her fears are really all in her head and a product of her vanity. Hence, we can call a second inner conflict vanity vs. circumstances.