Who is Isabel from Short Story Masterpieces and what is their importance?

Isabel is William's wife in the story, Marriage A La Mode, in which, she serves as her husband's main antagonist. Isabel love for her husband is unquestioned, her new love for the whimsical and carefree life of the artist society of England is. Isabel doesn't work, nor does she care for her children, but rather, she spends her time and money with a group of friends who simply pass the day lazily, with little ambition or goals. When confronted with William's emotions, Isabel shows her true selfish nature as she chooses her friends over her family.