A maidservant becomes the mistress of the house

I was the illegitimate daughter of a marquis, tormented to death by my legitimate sister for refusing to become a bedservant. Now reborn, I knew my destiny as a tragic side character had been rewritten. My sister, however, remained ignorant. Convinced she was the protagonist, she continued to torment me. I would teach her that in this royal household, I am the mistress, and my word is law.