Okay, so I was wondering what happened between Shen Xihe and the Gu family's daughter, and I have some useful info.

So this drama is not a rebirth. Both souls merged, so she is still Shen Xihe but has fragments of Gu Xing Zi as well as her memories. She's not looking for revenge for the Gu family because that was already settled when she died.

Her aim is to be powerful enough to protect HER family, as they have a lot of military power, and the emperor can decide to do them dirty because of that. So Shen Xihe is still the same, but has fragments of Gu Xing Zi. Her family means a lot to her; that's why she's thinking carefully about which prince to marry, who will serve her well.

I have seen Reuters, and there is a lot that hasn't been brought up yet