One small thing I noticed: the MC is careful not to slander the emperor in her thoughts when she's directly in his presence. She does it when she thinks he's not paying attention. That awareness that she has to control her even her internal voice shows she's smart and self-preserving. She's not careless she's just unlucky that he can actually hear her.
The little detail about the brothers and sisters having to do "exchange marriage" is a gut punch. It really sets the tone for how bad things are. It makes the family's poverty feel cyclical and inescapable. No wonder Yuan Tao is more worried about surviving than getting married himself; that system is broken.
2 The bamboo forest assessment was a bit of a letdown. I was expecting some cool trap or puzzle, but it’s just walking through and not getting lost. The incense stick timer added some tension, but the whole thing is over in a paragraph. Compared to the root bone examination which gets more detail, the second stage feels like filler. If the author is going to skip big parts of the assessment, why include them at all? Just have the MC picked directly.