Why is Xing'er called A Chu in Chu Qiao's Biography?

Chu Qiao originally traveled through time and came to Yuwen's house, but due to regulations, it could only be adapted into a story of amnesia. Chu Qiao became Yu Wenyue's maid, and Yu Wenyue named her Xing'er. Xing'er not only refers to her bright eyes, like stars.

It's because Yu Wenyue knows that Chu Qiao has a lot of energy! It is said that a single spark can start a prairie fire. Chu Qiao is as full of hope as the stars in the sky. It is also the hope of Yu Wenyue. Yu Wenyue has been fascinated by Xing'er from the beginning.