Since I don't have detailed knowledge of this novel, it's hard to say exactly. However, based on the title, the central character is surely the 'girl'. There could be other supporting characters like a love interest, a mentor - type figure who helps her understand her place in this 'different planet' situation, or antagonists who oppose her unique way of being.
In reality, fictional characters aren't real in another dimension. They are just figments of our creativity, existing only in the stories we tell and the minds that conceive them. There's no scientific evidence to suggest they have a real existence elsewhere.
I'm not sure specifically as I haven't read this exact story yet. But it could be some fantastical creatures or ordinary people put in extraordinary situations, which are common in Harris Burdick's works.
It could be that there is a male lead who is on a quest of some sort. Maybe he is trying to uncover a secret related to the events of 2001 in the story. And there might be a female character who is his ally or love interest, helping him along the way.
I don't have enough information to say who the main characters are. It could be anyone from an ordinary person trying to figure out their alternate lives to a more fantastical character like a time - traveler or a reincarnated soul.
Dialogue. In a novel, the language used by characters is often presented through dialogue. It's how the characters communicate their thoughts, feelings, and ideas to each other and to the reader.
There's Mary Santiago, a talented dancer. She's the Cinderella - like figure. Joey Parker is the famous dancer and singer who becomes her love interest. Her stepmother Fiona and stepsisters Brianna and Gabriella are the antagonists. They make Mary's life difficult, but Mary's kindness and determination shine through in the face of their meanness.
As the 'by another name story' is not well - defined here, we can only speculate about the main characters. It might be a group of friends where one of them has to go 'by another name' because of a misunderstanding or a secret they are keeping. Or it could be a single protagonist, perhaps a writer who uses a pen name ('by another name') and the story could be about their experiences in the literary world and how this alternate name impacts their career and personal life.
Without reading the story, it's difficult to determine the main characters. They could be Santa Claus himself if it's a story about his different adventure this Christmas. Or it could be a lonely person who becomes the central figure in a story of finding Christmas joy. Maybe it's a young child who discovers the true meaning of Christmas through some events in the story.