themes of autonomy

You are transported back in time and into the body of a young noblewoman in the 1400s. Your parents have married you off to an awful, abusive, rapist husband whom literally no one else would marry despite him being very high nobility because he's that terrible. You successfully produce a baby boy and then plan to murder this man for the good of everyone and yourself. Here is the question: do you think you could murder him in a way that is undetectable to the historical people around you? Note: they aren't stupid, you are the prime suspect as the battered wife AND you can't just say poison. Where are you going to buy poison? Do you know anything about poison actually? NO GOOGLING! You were sent back without a plan!

Edit: my notes are full of murder. I love you all

Edit: to clarify about the poison, you can use poison if you actually know how to identify it, I'm saying you can't just go "Poison!" with no knowledge about poison. Buying it probably means they know that poison and you're caught. Your personal knowledge when you read this post is all you have.

Another point of clarity: You went through all that trouble to have a baby without modern medicine so you could get the sweet house after your husband died. That's why you can't be caught. No disappearing.

Edit again: Air embolisms are going on a high shelf because the syringe won't be invented for 350 years. Prove to me that you could make one from scratch, lol