City C
It was a tiny city near the East Bridge. When Zhao Yanni was chased away by the Shu Family of Luo Hai, she came here with her physically-challenged child, Shu Xiner, with her lover.
The man was useless, as he managed to get by sticking with the Shu Family in Luo Hai but seduced the lady of the main house.
Even though he was able to get the lady, he could not stay in Luo Hai anymore. City C was not comparable to Luo Hai in any way, so he could not express his dissatisfaction anywhere else other than at the Zhao mother-and-daughter pair.
Zhao Ruoxin's childhood was unknowable. Mu Chenyan's urge to getting to know her was based on the abnormalities she exuded.
Before getting herself into the Yuan Family, she had had a romantic past with Xia Tao.
Based on Xia Tao's infatuation and age, Zhao Ruoxin was likely to have been in her middle school or high school when they got together, at least?