The Fake Heiress's Countdown, My GraveEpisode 4

Elise’s family sees a 100-day countdown above Evelyn, their adopted daughter. Believing she is dying, they grant her every wish—auctioning Elise off, shaving her head, stealing her company, and even giving Evelyn her husband and son. But the countdown is a lie. When it reaches zero, Elise vanishes instead. Only then do they realize they sacrificed the only person who had ever truly loved them.