What role does greed play in this story?

Mathilde believes that she is entitled to "everything".... that she has been cheated by fate and was meant to be wealthy and spoiled. Because of this, Mathilde insists on a dress her husband cannot afford, bought with money he'd been putting away for months, and refuses to settle for wearing roses instead of jewelry. As a result, she borrows a piece of jewelry from a wealthy friend (believing it valuable) and promptly loses it.