Just my two cents, not judging anyone for any of their kinks and not being critical of the author. Just noticed the terms used in the comments and wanted to weigh in while the projects is still early enough:
I am not a fan of the incest trope, but an even bigger peeve is renaming/recategorizing family members as Landlady and room mates. It's dumb. It's either an incest story or it isn't. Call it what it is. If it truly is not an incest story, then rewrite it so the NPCs are clearly defined for who they are as a person, not what they are to the MC. Make sure the dialogue reflects that difference and doesn't make anything feel weird because of it.
OR, have the incest, make sure any taboos are addressed, and go on with your story. I can accept it one way or the other, but not with a half ass recategorization.
A very bad example of this is My Best Deal, for reference.
I wish good luck on this project, and I am liking the premise. I will follow it to see where it goes.