@Karekon it WAS her mother. It was Feng Shen, having been reduced to low courtesan since she got pregnant and "abandoned" by Rakan, she was infected with syphilis and was left as a living corpse. It's explained in the novel, maybe later it will be explained here too
@Karekon not a LN or whatever reader but I'm pretty sure that is her mother. She was playing with white and black stones, like go pieces, the game she was supposedly unrivaled at. After he fucked off to war she was forced to regularly take customers and likely caught syphilis then. That's why Mao Mao made that bet with ol' dude to force him to finally fulfill his promise.
@Nicromatic I think she is, the one who both Mao and her step dad treated and the one who almost strangle Mao to death too. Note: I think she is still alive, she try to suicide, but cant move anymore
On another side, if Rakan arrived home as scheduled, after her price sinked, he will have the chance to redeem her, and maybe we will see a happy ending then. Sometimes fate is cruel
@Shyri she is, Fang Shen got pregnant with Mao-Mao when he is away on expedition. Its aligned with Mao-Mao story that she grow up in Hanamichi and raised by the three goddess, and one of them even become her milk mother.