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

Isabel is William's wife. She is also his primary source of agony. Isabel loves her husband, but her newfound love for the whimsical and carefree life of the artist society of England now takes precedent. She does not work, she does not care for her children, preferring to spend her time and money with a group of friends who simply pass the day lazily, with little ambition or goals. Her husband, the exact opposite, is ambitious, and has a great sense of family and loyalty. When confronted with her husband's emotions, Isabel shows her true selfish nature..... choosing her friends over her family.