Ah Duo’s child didn’t die in childbirth, he died shortly after. Fengming killed the baby by giving him honey. It was pretty much spelled out that Ah Duo was responsible for the baby switch because she thought her child would have a better life that way. And the entire reason that Ah Duo remained...
If her precognition is inevitable then there is no reason for her to abandon Pryde, because doing so won’t change anything. If she thought the future could not be changed then she should have just acted how she wanted. She sucks.