Shen Biran's situation isn't as bad as she thinks. If it were truly terrible, why would she have such emotions now?
She still has a chance to prevent Gu Qingyuan and Lu Xiao's scheme from succeeding. Lu Xiao and Gu Qingyuan will definitely not smoothly execute their plan against her daughter.
Moreover, Si Yuchen is also involved, which is one of the reasons for Shen Biran's confidence.
She trusts Si Yuchen, and believes that Si Yuchen is likely to earn even greater trust on this matter. It convinces her that choosing Si Yuchen as her son-in-law wasn't a wrong decision.
Whether Gu Qingyuan and Lu Xiao's scheme will succeed depends on whether they obtain Gu Xiaonuan's sympathy.
If Gu Xiaonuan is directly used by Lu Xiao, Lu Xiao will certainly not be happy.
Not only will she not be happy, but she'll be very angry, almost impossible to forgive Lu Xiao and Gu Qingyuan. This lifetime, she won't forgive those two who resorted to unscrupulous means to achieve their goals.
