It's not been said as such. There's nothing saying the mom is not a demon, but there's been hints that she's a human. People love the idea that such a forbidden romance happened not once but twice in the same bloodline and the exact next generation. Puts Henri in a good light, too, despite his work ethic.
It’s a fan theory without too much backing right now. But the idea is basically that it’s possible since her father was a border guard agent and could’ve somehow made contact with a human who’d slipped Through. meanwhile, the author Iruma worked for was Never shown directly and only their voice came through a closed door, as if their identity was intentionally being hidden. Finally that authors work somehow made it To Ameri, indicating some sort of connection between the author and her family
He already did. It didn't work. That's how he knew he was a thief
