Honestly a sequel to the true ending would just be a life sim. And it wouldn't have any drama because A the daughter can get anyone on the planet to fuck her with a whisper, and B all the people she wants to fuck are already willing.
The one to make a sequel of is the Heroes Daughters, just with a slight retcon. Make daddy dead. Then you have Daughter and Cath become the opposite of Grandma and the agent chick who's name I've forgotten. The game becomes a power struggle as you, the daughter, gain power and take actions against your grandmother's "family". You convince people to be your allies, fuck your way into places, force Cath to do the same. Honestly it would probably be one of the coolest games on here.