Yes, there are some. You can check out some fanfiction websites like Archive of Our Own. There are various stories that explore different aspects of a relationship involving raptors in the Jurassic Park universe. Some might be more focused on the adventure side while still having elements of a unique bond with the raptors.
I'm not sure specifically who created 'Jurassic Park The Real Story'. It could be a scientist, a journalist, or someone with a deep interest in both dinosaurs and the 'Jurassic Park' franchise.
Alan Grant is also a bit of a skeptic at first. He is hesitant about the whole idea of Jurassic Park. His character development throughout the novel is interesting as he goes from being a scientific observer to a desperate survivor, all while maintaining his scientific curiosity and integrity.
Since there's not a lot of common knowledge about a Jessica Harding in Jurassic Park fanfiction, she might be a unique creation within a specific subset of the fanfiction community. It could be that an author wanted to introduce a new character to explore different storylines, perhaps a scientist or a park visitor, but without reading the relevant fanfiction, we can only speculate.
Well, important characters include Alan Grant, who is really into dinosaurs and is kind of our guide into this world of resurrected prehistoric beasts. Ian Malcolm is also important. He's the voice of reason and warns about the problems with the park from the start. There's also John Hammond's grandchildren, Lex and Tim, who are in the park and add a sense of innocence and vulnerability to the story as they face the terrifying dinosaurs.