Agi Yaksa Hwangnyeonim

When Yun Chae-Ri gets sucked into her favorite game because of a strange scam, she finds herself as Princess Cherishe, a mastermind who must make one of her kin the Castalia Empire's next ruler. But this time, she's given a different mission: become the heir to the imperial throne and pay off her game debts! The only catch? She's stuck as a 4-year-old with no particular perks except her apothecary skills! Can this former kingmaker succeed in seizing the crown as a baby pharmacist?

(Source: Tapas, edited)