Shokei sareta Akujo wa, Taikoku de Kouhi no Za wo Tsukamu: Dokuhai wo Nomihoshita Ato ni, Yarinaoshi no Monogatari ga Hajimarimashita

Westalia, daughter of an aristocrat, has been brought up and educated with the expectation that she will become the future queen of her kingdom. However, when she is betrayed by a close friend and framed for an attempted murder, she is sentenced to death by poisoning. Luckily, Westalia, a master of poisons, manages to sneak an antidote, fake her own death, and escape with her life. Now on the run, Westalia must put her royal education to use as she steals her way across national borders, commits some crimes, and endures the grueling selection process to try and become empress of a neighboring empire and regain everything she's lost. All the while, an irritating man who seems awfully familiar seems to follow her at every turn. Still, with her loyal lady knight by her side, Westalia will do all that she can to make her dreams come true!

(Source: J-Novel Club)