The sentence fragment present in those sentences is...
Regina and her younger sisters.
In the story "The Necklace" by Guy de Maupassant, Mme. Mathilde Loisel borrows a diamond necklace from her friend when she is invited to a fancy party.
Mathilde has always wanted to belong to the upper class, and she gives a lot of importance to money and appearances. However, she does not have the money to sustain that kind of life. Therefore, she feels embarrased and does not want to attend the party as she says she has nothing that would suit the elegant setting. Her husband suggests borrowing the necklace from her friend. Doing so is very important for Mathilde because it is the only way for her to appear elegant and wealthy at the party, and to not feel dismissed or belittled by her low position in society.
Answer:
The sentence seems to be complete except if it is complete it needs a period to be actually completed
