"Is Xiaohong now in charge of the Crown Prince's meals?" the Empress asked.
"No, she is only responsible for cleaning the courtyard," replied the palace maid.
"I don't care what her responsibilities are, give her a package," the Empress said lazily as she stood up and walked to a cabinet on the side. She took out a package from a hidden compartment, "Give this to Xiaohong and have her find a way to put it into the Crown Prince's bowl when he eats. Once it's done, I will take care of her family for her, her brother in the Palace, and her parents and the rest of her family outside..."
In other words, once the deed was done, Xiaohong would undoubtedly die as well, but the Empress could cleanly wash her hands of the matter. Even if someone were to suspect her, she could deny everything until her death. The Emperor could depose her, but the Crown Prince's position would definitely be secured. Once the Crown Prince ascended the throne, she would naturally become the Dowager Empress.