Who is Si Wang-mu, Qing-jao's Secret Maid from Xenocide and what is their importance?

Every bit as gifted as Qing-jao but raised among the serving class, Wang-mu truly is a gem. Bold enough to manipulate her way into the position of being Qing-jao's secret maid, Wang-mu is instrumental in solving the disappearance of the Lusitania Fleet and in helping Han Fei-tzu loosen Congress' grip on Path. Her oppositional stance to Congress and questioning of the gods eventually lead to her dismissal as secret maid but Han Fei-tzu retains her as a servant in name but "daughter of his heart" in practice.