It isn't common knowledge even for native English speakers; but the form of, "thou" is actually the informal voice. Romance language speakers would recognize their equivalent of, "Tu".

The noble lady would be using, "Thou" to address the servant.

Most native English speakers wouldn't really notice anyway since the formal / informal purpose of, "you / thou" stopped being used commonly in the 1700s; but I figured I would share.

Quite interesting to read, thanks for the knowledge :D

Haha I was imagining I must sound like such a pedantic, "WELL AKSHUALLY!" nerd.

Naah, not to me, I'm like that aswell.

According to the notes of Diana Gabaldon, the Quakers persisted in using “thee” until the 20th century, the last remnant of their ‘common speech’.

Oh interesting and thank you for citing a source; more thorough than I was!

I wonder if it had to do with their concepts of egalitarianism that they were still using the informal voice long after it had become an anachronism.

Sounds about right.

"it's hard to be patient at any age"
Ain't that the truth