Wait, the Villain Is a Nanny's Daughter?

In the Cafaro Empire, Hailey served the noble lady Natalie from childhood, and the two of them came through years of difficulty together. Natalie became empress. Hailey was raised to a high-ranking concubine and ran the harem alongside her, and she was still working at the palace at sixty. Then she wakes in another era as the daughter of the Smith family's housekeeper. The Smiths have just brought home their real daughter, also called Natalie, fetched back from the countryside, and her face is the same face Hailey served for a lifetime. This Natalie is bullied by Mila, the girl the Smiths adopted and raised in her place, and she is too frightened to answer back. The parents take Mila's side. Hailey decides to stand with Natalie, deal with Mila, and take on the parents who favour her.