One possible theme could be hope. If Laura is in a tough situation and the star represents something to look forward to or a guiding light, hope would be a theme.
I think friendship might be a theme. If Laura has a connection with the star, it can be seen as a form of friendship. Also, wonder and magic could be themes as the star likely has some extraordinary qualities.
Survival could be a theme as well. If the story is set in a difficult environment, like a post - apocalyptic world or a harsh wilderness, Laura might have to fight for her survival. This could involve finding food, shelter, and protecting herself from danger. Or it could be a story about family, with Laura having to deal with family issues, like conflicts between family members or trying to keep her family together in tough times.
One possible theme could be transformation. Since Laura is saying 'so long' to normal, she is likely undergoing some sort of change.
One theme could be change. As the title implies saying goodbye, it suggests a shift from one state to another. Maybe the character has outgrown the relationship with Laura or the situation she represents.
Maybe Old Joe made fun of Laura in front of others. If he mocked her appearance, behavior or something she had done, it would be a reason for her humiliation. For example, if Laura had a hobby that she was a bit self - conscious about and Old Joe made jokes about it in public, that would be quite humiliating for her.
One possible theme could be love. Esther might be in love or searching for love within the Persian context. Another theme could be identity. She may be struggling to find her place in Persian society. Also, the theme of family might be present as family relationships often play important roles in stories set in different cultures.
One possible aspect could be her personal growth. Maybe she had to overcome challenges in her education and that's part of the story.
Given the lack of information about Grace Laura Story, her achievements could be diverse. If she is part of a community, she may have achieved recognition for her volunteer work, helping to improve the lives of others. In a business context, she could have led successful projects, increasing revenue or efficiency for her company. She might also have achieved a high level of skill in a particular hobby, such as becoming an expert in a musical instrument or a form of dance. It all depends on what she does and who she is in her life.
Another theme could be mystery. Given that it's a 'secret' story, there's likely an element of the unknown. It could involve Laura trying to solve a mystery, like a missing object or a strange event that happened in her town.
One possible theme could be exploration. Since it's about stars, it might involve the exploration of the unknown regions around the Delphinus stars.