Some of the more crazy ones do it though - obviously by prostitution. They get their lover to kill their husband, boss or whomever.
Discussion
Yes, I've consumed enough true crime to understand the female killer MO. It's incredibly rare for a woman to do the job themselves when the target isn't a child or somebody too elderly and/or infirm to fight back.
Sad thing is that in that regard there enough weak, easilily manipulated men out there that behave as if the Dune universe Honored Matres were real.