It's likely fictional. There's no concrete evidence to prove its authenticity.
Most experts consider it fictional. The story seems to lack reliable historical or scientific support.
A practical answer is Chapter 13, because it turns the idea into a concrete scene. The chapter opens with Sensing that something was off with Jiang Yan, Jiang Yan dismissed the..., adds pressure through He probably had a good guess who it was., and ends on How could this happen..." Lin Manru.
Chapter 910, "This place isn’t fun, I want to go home!", is the clearest early answer because it turns Wan Hui's situation into a concrete plot event. Early on, Jiang Bufan was not very shy.. By the end, It's all sister's fault for bringing us here..
Look to Chapter 5 for the clearest answer. It begins with Actually, when Manager Fang saw Jiang Li, he was somewhat surprised., keeps building through Because she was really too beautiful, and very young, completely different..., and lands on Recently, he did suspect that his wife was cheating on.
If you want the clearest chapter reference, go to Chapter 11. Early on, After a meeting, Shang Shaojing pinched the bridge of his nose, tired, and...; later, the chapter leans on How is it going with the Jiang Family?" The assistant looked troubled and....
Look to Chapter 34 for the clearest answer. It begins with Seeing that the public sentiment wasn't quite right, Su Yinwan felt..., keeps building through It was she who had anonymously paid someone to write the critical article..., and lands on Now that Lili is misunderstood, they start to kick us.
Look to Chapter 9 for the clearest answer. It begins with Exactly, the Qiao Family isn't that great either., keeps building through They've been yelling and shouting since morning, with no sense of decorum..., and lands on Qiao, unable to save face, slapped her daughter across the face, "Didn't.
The best chapter pointer here is Chapter 31, "Master, I've been having some bad luck lately!". It opens with Before Shen Lan had reached the backyard, she already heard the sounds of... and closes on After staying in the study and reading for another day, she finally....
Chapter 907, "Disgusting Clothes", is the clearest early answer because it turns Jiang Bufan's situation into a concrete plot event.
Chapter 17 is the strongest chapter-level answer because it starts from Jiang Li glanced at Jiang Shixu, who was tense and anxious behind her, and... and follows through on I've been a mother for more than ten years but never tasted anything made....