Divorce the Fake, Marry the Throne

Reincarnated as the Bingley family's abandoned wife, Cordelia is betrayed, slaved for them, then cast out. When her ex returns to steal her fortune after faking his death, she divorces, takes her inheritance, and vanishes. At a royal banquet, the Bingleys realize: the kingdom's most powerful Regent is Cordelia's new man, who truly loves her and has the power to back it up.