I think if she died, Lin Xiao would have been burdened and guilt tripped by her death and this would carry on for the rest of his life, with no way to remedy it. I’m aware that mental health is quite downplayed in Asia. But she obviously has some serious mental health issues that need to be addressed that this show was way out of its depth in portraying. I think she was finally confronted with the fact that SHE was the toxic person in her sons life and the best way for her redeem herself was to live on without trying to control and patch up a relationship the way she wants.