Mills: Female Servants Usually Employed At
Source: TTT
Exodus 11:5
and every firstborn son in the land of Egypt will die, from the firstborn of Pharaoh who sits on his throne, to the firstborn of the servant girl behind the hand mill, as well as the firstborn of all the cattle.
Matthew 24:41
Two women will be grinding at the mill: one will be taken and the other left.