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.
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.
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.
I really like 'Klaus and the Unlikely Companion'. In this fanfiction, the OC is a witch who crosses paths with Klaus. What makes it stand out is the way it portrays Klaus's vulnerability around the OC. It shows a different side of him that we don't often see in the show. The plot twists are also quite engaging.
A 'a family affair tvd fanfic' could be about different family - related storylines. It might be about a family that has just moved to Mystic Falls and how they get involved with the existing families in the show. Or perhaps it's about a long - lost family member of one of the main characters showing up and causing chaos. It could also explore the family trees of the vampires and werewolves in the show, and how their family legacies impact their actions and interactions.