I do think she's ameris mom but I don't think she's the mangaka or
1. maybe she could've found some way to bring manga after marrying Henri n Henri lied n told ameri it's a family heirloom
2. She's the mangaka she worked on the manga in the demon world n continued it when she got out hence we get iruma being her assistant since there is such a heavy focus on her being able to draw( Also it couldn't be an old family heirloom cause it's a new manga)
3. Unlikely but it could be that she made the manga after she left demon world n Henri bought it to demon world to have a monento of some sorts near him











Loveddd it omg if u want like a not serious funny parodyish story go for it