I imagine there would be signs of struggle if she tried to overpower him. It was a much smarter move to play as a wife visiting dying husband and hearing his last words. Even when he got paranoid and thought she was the one poisoning him all along and tried to stab her, the situation was still salvageable(she could hide the knife easily and say the pharaoh had a violent outburst and knocked things over while at deaths door, no one can question a corpse), where as forcing it down his throat would be much messier and harder to bullshit. Even while severally weakened,the Pharaoh could probably do shit like hold his mouth closed and bite your hand. Which means she would have to explain why she had bite marks on her hand and why the Pharaohs drink was spilled around his head, at which point the priests would frame her as the one doing the poisoning all along. makes sense?Seemed last parts were blue if so why say it when you can easily overpower him and give the poison.