As we don't have much information about this specific story, Jenna could be a protagonist who is a slave. She might be a symbol of the resilience of slaves in the face of the cruel institution of slavery.
Jenna is likely the main character in the story. She could be a young girl, a teenager, or even an adult. Since the story is named after her and the black cat, she's probably the one whose experiences are central to the plot.
I'm not sure specifically which 'king of slaves jenna's story' you are referring to. There could be many fictional or historical stories with such a title. Maybe it's a story about a character named Jenna who has some sort of connection to slavery, perhaps she was a slave herself and had a journey of struggle and survival in that harsh system.
I don't know what you want to know about Jenna's novel. Please provide more background and context information so that I can better answer your questions.
Jenna Ortega is a relatively new actress compared to the time when Pulp Fiction was made. Pulp Fiction came out in 1994, and Jenna Ortega started her career much later. So, there is no connection between her and the movie in terms of her being in it.