Yin He had siphoned off projects from the Yin Group and secretly introduced them all into Ze Yi Company. He fooled Little Ze's mother into being the legal representative of the business, which was registered under her name, but Little Ze's mother didn't understand a thing about running a company, so from start to finish, Yin He was the actual person in charge.
Upon learning of this, Yin Zhen finally understood why Little Ze's mother was willing to take the blame for poisoning her on behalf of Yin He.
One reason was Grandpa Yin's attitude of not airing family scandals and quelling disputes quietly; the other was that she had been so beguiled by Yin He that she believed the company was hers, the child was hers, and naturally, the money they made was also hers.
So, even if Grandpa Yin had "sent her away" to soothe Yin Zhen, who was poisoned, she wasn't the slightest bit panicky.