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.
Well, without more context regarding 'PLL Book 12', it's really difficult to name the 5 novels. It might be that this is a very specific collection within a certain series. Maybe if we knew more about the overall theme of the PLL series, we could make a better guess.
I'm not sure specifically which 'pll' you are referring to. It could be 'Pretty Little Liars'. If so, it's a story full of mystery, secrets, and drama among a group of friends who are being tormented by an anonymous 'A' who knows all their secrets and uses them to play cruel games. There are lots of plot twists and turns as the girls try to figure out who 'A' is while dealing with their own personal issues like relationships and family problems.
I'm not a fan of online literature. I'm a person who loves reading novels. I can answer all kinds of questions based on the knowledge I've learned. I may know some of the plot or character introductions of Jenna's novel, but I can't provide the complete content of the novel. If you have any questions, please let me know and I will try my best to answer them.