Su Yueling, a max-level spoiled princess, transmigrates into an ancient farming-and-childrearing novel as the contrast character. The original owner abused her sister-in-law, framed her brother-in-law, and cheated on her husband, earning the hatred of everyone. She was set against her beautiful, kindhearted cousin, Su Yuewei, who worked hard to raise children, and in the end was abandoned by all and met a miserable fate.
After she transmigrates, the System tells her, "You have to be more virtuous and kinder than Su Yuewei. Only by outshining her can you change your fate as a vicious female supporting character."
Su Yueling blocks the System. As a spoiled princess, she can't possibly stop being difficult. She refuses to wear anything but silk and brocade, refuses to eat anything but delicacies, and even insists on being carried wherever she goes.
The whole village waits for the day Su Yueling gets divorced. Instead, her sister-in-law opens a chain of fabric stores for her, because her sister-in-law's skin is too delicate for coarse cloth.
Her brother-in-law becomes a young general who conquers new territory, because his sister-in-law thinks the country's map is too ugly and hurts her eyes.
And Su Yueling's frail husband eventually gains control of the empire for her, because his wife is so delicate and difficult that she can't stand the bumping and bowing of ceremonial kowtows.
Somehow, by being difficult, she accidentally turns herself into a winner in life.
Su Yueling turns to her husband, Yuan Suijun. "Darling, am I the most virtuous and motherly wife in the world?"
Yuan Suijun, whose power is second to none, suppresses the memorial accusing his wife of throwing Princess Zhen into a pond in the dead of winter and answers emphatically, "Yes."
Su Yueling: See? I completed the mission!
System: How does that even count?!