There's not enough information to say exactly who Kathy is. She could be an ordinary person with an interesting life story, or she might be someone known in a specific community or field.
Chen Kaixi was an assistant director. His representative works included the short film, The Clock That Was Two Minutes Slow. In addition, Chen Kaixi also played a role in the TV series Dear Enemy, played by Chen Yanxi. There was no other information or background information about Chen Kaixi.
I don't have enough information to say exactly who Cap'n Kathy is. She could be an original character created by the fan fiction writer. Maybe she's a pirate - the 'cap'n' part could suggest that - who has some connection to the wizarding world of Harry Potter.
Kathy Andrews could be an ordinary person around whom some interesting stories are woven. Maybe she's a character in a local folklore or a self - published collection of stories. Without reading the actual stories, it's difficult to say more about her.
The origin of Kate Kane and Jacob Kane varies in different comic interpretations. Kate Kane is known as Batwoman. Her origin often involves her military background and her decision to take on a vigilante role in Gotham. Jacob Kane, her father, is also an important figure in her story. He has his own military and family - related past that intersects with Kate's journey.