Shen Biran is not in a vegetative state, nor does she show any symptoms of being in one.
However, her acting skills are good, so she deceived many people. Perhaps Shen Biran has her unspeakable reasons, but she still hurt her daughter.
Shen Biran's disguise caused Gu Xiaonuan to spend many years running around for her condition. Without this, Gu Xiaonuan wouldn't have become his wife and signed a prenuptial agreement with him.
Shen Biran is Gu Xiaonuan's mother, and Si Yuchen should naturally give her the minimum respect.
However, this respect is not given sincerely.
Si Yuchen is still unfairly indignant on behalf of Gu Xiaonuan's many years of hardship because Shen Biran deceived even her closest family members to achieve her goals.
Gu Xiaonuan knows the truth but doesn't expose Shen Biran; she hasn't done so.