Evelynn also couldn't say anything.
As members of the Davis Family, they all followed Davis's teachings. The children were particularly made to recite the Ten Commandments every week in their childhood.
It was literally in the Ten Commandments that he had established, which they had to follow to the best of their ability in order to maintain unity and peace of mind.
[You shall try to endure insults that are not true as you will accept compliments that are not true— with a humble face that's dismissive.]
[You shall not be overly righteous or willfully evil— stay in between the lines and remain smart enough to keep your horizons clear of mist at all times.]
[Spare lives as much as you can. You shall only commit murder for the sake of the family— not to be abused or used against the family.]