I was excited, I really thought poison would be a way to implement a powerful, thought-provoking binary yes/no choice through clever in-game mechanics instead of dialog options. I seriously considered giving her the poison, I spent some time thinking, decided I wouldn't, then thought if I kept giving her other drinks (maybe if I made one that altered her mood in a specific way) she would relent. It's just kind of disappointing that you set up the pieces so perfectly for that but it wasn't actually a mechanic.
Poison is really the most interesting aspect of the whole game. There are other games like yours, but none with something like that. I wish I got to see the people in your game's universe who can legitimately drink it unharmed. I wish the assassin could detect it because of his work experience. I know that wasn't the point of the game, but it would be fascinating to see the consequences of using such a bizarre ingredient.