This is a promotional webtoon for the novel of the same name 3l6953

Emily Renedelle, a seventeen-year-old noble lady, was having a peaceful dinner with her family when the atrocity befalls her. She watches a group of intruders slash her parents and her older sister to death. Terrified, she tries to crawl away, but the ruthless Duke Samuel Kleiphen slices her neck without hesitation. She dies cursing the man, and the next thing she knows—she wakes up in a different body whose owner is also within an inch of her life. Now in the body of twenty-six-year-old Jane Serengti, Emily has no choice but to accept the reality that she is given a second life as an impoverished woman burdened with massive debts. To her relief, though, she learns that her soul has traveled back in time five years prior to the tragedy. She also manages to land a job with handsome pay as an etiquette tutor at a duke’s manor. Little did she imagine that she would be tasked with disciplining a headstrong boy, who turns out to be the very man that had killed her! Has fate granted her the chance to avenge herself?

Original Novel/Promo

Note:
According to reviews, the novel is tag as R19 but the series doesn't seem to have R19 content (esp Vol.1-2), this could mean the series is tag as R19 due to the heavy themes around it instead. Another review did say Vol.1-2 are all-age while Vol.3 is R19 despite the whole series being tag as R19.