To clear up the Royal Titles: Gerald is a Grand Duke which we can assume he inherited from his parents. Violet’s father is a Grand Duke and should be the reigning monarch’s son, thereby making Violet a princess. If she were to succeed her father, her title would be “Her Royal Highness, Princess Violet, Duchess of <insert land here>”.
As for Shannon, Russel, and Aaron- God knows.
I think we’re all princes and princesses at this point so we better own it.