I think she's being fully honest as to how she feels and what she thinks oniichan's concerns are. It might seem like she's intentionally still trying to manipulate him, but I don't think so. It just kind of seems like that because she's somewhat insane and codependant.
This whole chapter, I couldn't help but get a foreboding feeling. Is the mom the final boss, or is there a stronger force that they have to take care of? I don't think things will go as smoothly as the mangaka's other incest manga (and that was far from smooth).
. This is only revealed way late into the webnovel. It hasn't been adapted to LN yet, but if it were, it would be about LN 25 or so. The webnovel is way ahead of the light novel
I love how someone basically called Fran a psychopath to her face. The depiction of the evil god communion was interesting, though I can't help but be reminded of the lolicon crying emoji.
For the record, the 18+ doujin does show that while they are still sex friends, the girl is warming up to him. Will he fix her? ... Eh, that's probably over optimistic
... Well that was fast, but not too surprising. The more surprising thing is that the mangaka made a doujin about it. Eh, sure, I can spare a few bucks.