The Murdered Princess and the Innocent Traitor

The Murdered Princess and the Innocent Traitor summary:

Brigit, who has spent her entire life as a commoner orphan, finally reunites with her brother, the emperor, and her sister, the princess.
Just as she begins to envision a bright future with her family, she is brutally murdered by her own siblings as a sacrificial offering on her coming-of-age day.
Now, her life is turned back by Nidhor, the evil dragon, and she awakens as a commoner who has yet to find her family.
Knowing that she is sure to face death should she return to the palace, she decides to flee the empire quickly and finds a job as a sorceress.
However, by a twist of fate, she lands a job at an enterprise run by the traitor duke...
Will Brigit manage to successfully fulfill her contract and escape the empire?

Official Translations:
English, Japanese, French