Muxi is a traditional ancient-style noble young lady. This is a fictional historical novel, so please don't scrutinize the historical details too closely.
The heroine is meant to be exceptionally bright and perceptive. Children in ancient times matured early. If you don't like that, consider Daiyu from Dream of the Red Chamber: she hadn't yet reached fifteen when she died, and Jia Yucun began teaching her at five. I won't go into the details of when she entered the household. Feel free to drop the story if it's not for you.
This story focuses on the quiet rhythms of everyday life, though there are occasional twists. If that's not your thing, read with caution.