Let's see...
Empress Evgenia
Empress Dowager Elena
Duchess Daria
Marquess Maria
Princess Polina
Tsarina Tarakanova
Archduchess Alina
Archduchess Alena Kostornaya
Archduchess Alexandra
Sultana Sofia
Sultana Stanislava
In fact, tsar, kaiser, etc are all derived from the name of Caesar, which makes them equivalent to the title of emperor, and the only difference is nationality.
Considering that Alina is the only senior knyaginya, the proper titles should be:
Tsarina Evgenia
Tsarina Elena
Duchess Daria
Duchess Maria
Knyazhna Polina
Princess Tarakanova
Knyaginya Alina
Knyazhna Alёna Kostornaya
Knyazhna Alexandra
Velikaya knyazhna Sofia
Velikaya knyazhna Stanislava