Maomao is confirmed to be a child of Lakan (the monocle-wearing freak strategist) and a courtesan Fengxian from the Verdigris house. Maomao is still employed by Jinshi as his assistant/maid but she's currently "on loan" to Gyokuyou who is pregnant and needs more help and a better food taster (hence Maomao).

Thanks for the refresher. I haven’t watched Season 1 since it wrapped up, so I must’ve forgotten.