She is the princess who fought for others but didnt have a strong support
When ML rebels (he loves her and dod it for her to be empress) her sister poisons her (sis is pregnant with something) the ML returns time and now she strive sto have his as personal servant and be crown princess
She prevents her poisoner sis from getting him and meeting him, gets in emperor good graces and cuts off the future crown princess
The Princess Imprints a Traitor