Input (grade 13): Anastasia's title is most precisely translated as "Grand Princess," meaning that Anastasia, as an "Imperial Highness" was higher in rank than other Princesses in Europe who were "Royal Highnesses."
Output (grade 8): Anastasia was a Grand Duchess. Because this made Anastasia an "Imperial Highness", she was higher in rank than other Princesses in Europe who were "Royal Highnesses".