Saving the Villain From the Heroine

Ever since she was suddenly possessed by a sub-character in her favorite novel, Random Box, Ciel's goal in life has been to become the head maid of the villainous Grand Duke.
However, when the Grand Duke is killed by the female lead, Ciel's goal is thwarted. In the end, Ciel saves the Grand Duke and is cursed to become a child instead.
To break the curse, she must become the adopted daughter of an even worse villain?

Can Ciel survive the villain's lair and return to adulthood?

Original Novel:
KakaoPage, Naver Series, MrBlue, Joara

Official Translations:
English