Ya know, when a woman first finds out her husband has betrayed her, many emotions and thoughts go through her. Sometimes the thought of killing him, and/or the other woman will come to mind. And it's not like some women don't follow through with that thought, all you have to do is watch "Snapped" or "Deadly Women" to see of often is does happen. But most women, even if they have that thought at some point do not follow through with it. Most get their senses back and get rid of the cheater and find someone who is going to treat her like the princess she is.
Why risk your life, your freedom, your reputation to become a murderess and then keep the moron that started it all? Even if she got away with this one, Old Sidney probably would have found another HE down the line and TM would be right back in this same situation again. After all, once a cheater, always a cheater. IMO