One possible theme could be royalty and power. It might show how the princess deals with the power and responsibilities that come with her title. Another theme could be love, whether it's love for her family, her people, or a romantic love.
One possible theme could be class differences. The princess is likely from a high - class background while the marine is from a more common, military - oriented background.
One possible theme could be creativity. Since it involves a 'yarn princess', she might be creating all sorts of things with yarn, showing off her creative side.
Friendship could also be a theme. Since she can't rely solely on her royal status, she has to make real friends. Through her secret, she might attract people who like her for who she is, not what she is, and these friendships help her in her journey in the 'the secret princess story'.
Another theme could be survival. If it's a story about individuals or a group, they might have been facing challenges and trying to survive in the conditions of 1922, which could include economic hardships, political unrest or natural disasters.
Love is probably a major theme. The prince's search for his princess is centered around love. Another theme could be adventure, as he likely has to go through various adventures to find her.
One possible theme could be courage. The little princess might need to be brave in the face of difficulties.
Well, the theme of discovery is quite likely. The diaper girl princess discovers new things about herself, her kingdom, and the magic around her. And there could be a theme of courage too. Despite being in diapers and perhaps seen as vulnerable, she has the courage to face challenges in the kingdom, like standing up to a mean witch or helping a lost animal find its way home.
It could be a love story. Princesses are often associated with love, and perhaps she's reading about a great love that overcomes all obstacles, much like her own relationship might be.
One possible theme could be self - discovery. The princess might be on a journey to discover her true self as an adult, away from the naivete of her youth.
Well, themes in the 'Dark Princess' novel could include love and betrayal. Maybe she falls in love with someone she shouldn't, or she is betrayed by someone close to her. Also, redemption could be a theme. If she has done something wrong or has a 'dark' past, she might be on a journey to redeem herself.