I don't have enough information to specifically say who Roman Coleman is in this 'true story'. It could be an ordinary person with a unique experience, or perhaps someone who has made an impact in a particular field but is not widely known outside of the context of this story.
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, Coleman science fiction might often feature advanced technological concepts. It could have unique alien species with their own cultures. For example, the stories might explore the implications of time travel or faster - than - light travel.
I'm not sure specifically as I haven't read it. It could be about a place called Coleman Hill and the events, characters, and stories that unfold there.