You've lost me there. I didn't get the "reasoning."
Servants used the terms “sir” and “m’am”. She believed that here grandchildren would **have** servants and would never be a servant.
She was born into an extremely wealthy family, and her father was friends to the king.
So....Even now we do not call people “sir” or “m’am”, and we would prefer that others not use “sir” or “m’am” to address us ( except in the military). I realize that in the United States that “sir” and “m’am” are merely a form of politeness, but to my granny it evoked memories of rigid class-ism.
I believe that my great grandparents ( even though wealthy) came to the U.S. with their family to escape suffocating class ism of late 19th century England.