I’m a Mother-in-Law, but I Dislike Conflict with My Daughter-in-Law

Our perfect daughter-in-law (older) didn’t seem to like me.
“Grandmo … no, Duchess, may I stay over tonight?”
In the midst of this, the noble young ladies I had criticized began to regard me as their grandmother back in their hometown.
I married an old duke, but my husband died the day before the wedding.
So all of a sudden, I ended up becoming the great madam of the duke’s family.
For your information, the son and his wife are older.
“Let’s live quietly together.”
A full-blown mother-in-law and daughter-in-law romance fantasy conflict story.
A modern mob person who doesn’t understand high society.