I'm going to fire my weapon at a defenseless woman
Why would you do that?
The woman was my friends wife and she poisoned me so many times. I'm fed up with her shit.
Firing a weapon at her is not the way to solve this. You should alert the authorities about your incident and not take it into your own hands.
She will get her just deserts.
If you give her what you think she deserves with violence, then you will get in trouble too. If instead you alert the police to her attempts to poison you, then she will go to jail and you will be free to live your life. Also, you should not injure or kill other people, even if they have tried to kill you.