Seducing the Monster Duke - Vol. 1 Ch. 46

[MangaDex]

 

[tuuesnier]

DING DONG THE BITCH IS DEAD!! THE REEKING BITCH IS DEAD!!!

 

[SAMEMAN1223]

So uh this can go two ways with my theory. Old lady is her or the Duke's mother. Also if she cared so much for that "Child". The "Child" could be the Hero or the Duke. I think some weird backstory about how the Duke wasn't blood related somehow and one of his parents deeds caused the mark. That would make my second theory makes sense that the old lady is the Dukes true mother.