Jessica Harding is Gerry Harding’s youngest daughter and half sister to Dr. Sarah Harding. We know this due to in-game dialogue. Jess was joining her father on Isla Nublar when the incident at Jurassic Park occurred.
Little is known about Jess’s past except for her trouble with the law, having stolen items from the mall. Jess also demonstrated theft on Isla Nublar when she stole viewing binoculars and telling Gerry that it was a gift from John Hammond (referred to as John Hammers by Jess). Theft was the catalyst for sending her to Isla Nublar with her father. Jess also has a tendency to be rash and disregard her fathers orders and established rules, demonstrating this many times throughout the game by sneaking off and getting into troubling situations. She seems to dislike the fact that her father left and wishes that he will move back to Dallas.
Jess shows that she is the curious type by asking a lot of questions to the likes of Dr. Laura Sorkin, Billy Yoder, and Oscar Morales. It is also known that Jess took Spanish and at one point after she uses her skills to tell Nima Cruz (who is suffering from the effects of Troodon venom.) to get some rest in Spanish. Other skills include the fact that she can drive (a skill hidden from her mother.) and her knowledge in diving when she received once again secret, diving lessons from her mother’s boyfriend.