You've Been Wronged?

In the hall, Si Qi, with her hands tied behind her back, knelt in front of Princess Yongle, shouting grievances loudly. "Princess, I've been wronged! I have followed the princess and the consort for many years. I'm loyal and uncompromising, and the world can testify to it. How could I do such a thing as poisoning and harming the consort? I ask the princess to investigate it and be the judge of me!"

Princess Yongle glanced at Yang Yiting with an embarrassed look on her face, obviously still not convinced that Si Qi was the servant who poisoned the consort.

This servant had been with the consort for many years, and had always been favored and trusted by the consort. Although she was a close-fitting servant, the consort had always been kind to her. Among all the maids serving the consort, she was the most favored. Why did she poison the consort to death? What good would it do to her if she killed the consort?