Responses
I think because she wants the company and the only way is through a child, like jinyao and his cousins. I forgot where I read this, but she stole fengs so it can be of family blood, since she is female its not direct. I COULD BE IMAGING THIS OR CONFUSING THIS STORY FOR ANOTHER BUT I SWEAR THIS IS WHAT HAPPENED
so rourou isn't blue hair's biologically, brown hair switched the embryo and stored blue hair's for the future-- no idea why that hag got the embryo but the newly introduced baby is blue hair's, which makes rourou his/her stepsibling aka sidekick (´∩｡• ᵕ •｡∩`)