Sarah understood best that her manner of life was frowned upon by many people, although it had become legal in some ways.
There weren't many females that were like her and came out to the world about how she lived her life.
She would rather be mocked for what she believes in than be called a hypocrite.
Some may believe she is pushed into this lifestyle, particularly her family members who are aware of the system, given how the system is constantly assigning her tasks to keep adding boys to her harem, but she is fully aware of herself.
That dark half of her, hidden from the rest of the world, is thoroughly enjoying herself. She enjoys it, which is why, even if she acts angry at times, she will still go out there to find another guy and welcome him home.
However, what she does is not what she truly expects from others, including her own children.