According to an article in the Health section of U.S. News and World Report, the reason why many women going through divorce seek revenge on their spouse is fairly simple: human nature.
Michael McCullough, professor of psychology at the University of Miami, says when a woman -- or a man -- tries to exact revenge on their ex-spouse, because of their ongoing family law matters, she is simply doing what her brain programmed her to do in satisfying senses of desire or craving to produce what she considers a reward. He claims the brain activity in someone carrying out revenge is actually similar to the brain activity found in an Olympic athlete who trained for years in order to win a gold medal. Both are associated with pleasure.
McCullough believes that somewhere along the line this must have been planted in the human brain by natural selection. By making sure individuals act to protect their own interests and punish people who act against them, the species is better equipped to survive. Divorce is a situation where these feelings and urges come into play.