A few reasons I'd say, but the most important one being the current contrast of high- to low intensity episodes that make up the gameplay.
As an example: The moment Gina learned that Jade was a prisoner of the Genovannos, everything else instantly lost relevance. No training, no other story elements, certainly no romance... the one and only thing that counted was getting Jade out despite any risks involved. The same would be true if Gina leaned that her own mother was killing people in under Genovanno command. A threat or personal story arc like this would blend out all other things I still want Gina to do.
To fix this I would have to give a reason to Gina to not pursue this, for example, her mom being in full control of her senses and has chosen this path, etc. but nothing felt right. And there is ofc. the whole suspension of belief thing too 😅
you could also do it somewhere close to the ending, or you could make a chapter that focuses on this and uncovering what happened with the mom. This way you wouldn’t have to rush the reveal and consequences.
Think of it as a detective chapter, maybe even with the chance to redeem or at least change her a bit.
Or you just go for the Amazonian Chosen Warrior Goddess Gina beating the shit out of now comparatively tiny executioner