Lex Murphy

Lex Murphy was John Hammond's granddaughter and  Tim's older sister who accompanied the group on the tour because her parents were getting a divorce.

Jurassic Park (novel)
Lex Murphy is first seen in the novel coming out of a helicopter with her brother, Tim Murphy. Grant guessed she was no older than eight years old. Donald Gennaro expressed his outrage that John Hammond would allow children on the test tour. Regardless, the children tagged along. Lex accompanied her brother and Ed Regis in the first car as they began the tour. She quickly became bored watching the dinosaurs do nothing and was glad to hear they were going back.

Unfortunately, Dennis Nedry took that opportunity to cut the power off and the T-Rex seized that opportunity to break through the fence. Lex and Tim stayed in the car as the dinosaur picked it up. Lex fell out of the car and was knocked unconscious. Lex awoke in the middle on an empty road to find Alan Grant at the edge. They eventually found Tim and Ed Regis, but Regis was killed before they could do anything about it.

The three began to walk through the park, trying to trip the motion detectors. The three spent the night in a storage room where Lex befriended a juvenile triceratops. The group eventually found a raft and managed to out-paddle the T-Rex. The group follows the river back to the main entrance and finally, after one final encounter with the T-Rex, made it back to safety.

Alan Grant put the two kids in the kitchen while he worked with the other adults. The kitchen was surprisingly ambushed by a single velociraptor that the siblings managed to trap inside a meat locker. Knowing that there was nowhere safe, they began to help and were met up with Grant and Gennaro as they finished off the raptors.

The building was finally safe as they returned to the Control Room and managed to call for help. Lex and her brother were picked up by one of the helicopters before the island was bombed. Lex appeared playing in the hotel pool with her brother while Dr. Marty Guitierrez explained that the children would be allowed to go home, but the rest would be staying in Costa Rica indefinitely.

Jurassic Park (film)
In the movie, the roles of Tim and Lex were more or less reversed; Lex was now the older sibling, and she was given Tim's skills as a hacker. Nevertheless, Tim became the younger sibling, but still kept his fascination for dinosaurs.

She along with Tim are first seen when they happily greet their grandfather as he brings the other guests down to take the tour car from the park. Outside, she becomes fascinated at the interface the car had for the tourists. In the film Lex is portrayed as the older sibling of the two and adoring grandchild of Hammond. She is shown to be rather indifferent towards the dinosaurs which eventually turns into a dislike and fear of them due to her and Tim's encounter with the T-rex. She is considered to be easily intimidated and does not enjoy being very close to dinosaurs unlike her brother. She also has very good computer skills and is a proficient computer hacker. She is initially shown to be optimistic and enthusiastic at the beginning of the first film and has an understandably juvenile personality. Though liked by Dr. Sattler she is shown to be disliked by Dr. Grant whom she is ironically shown to have a crush on, but Grant later learned to like her and she was shown resting on his shoulder in the helicopter back home. After the the events on the island it is assumed that she went back to live with her and Tim's mother who is presumed to have custody over the children from her failed marriage, due to Hammond being her biological grandfather and having access to a large amount of resources.

The Lost World (film)
She and Tim briefly meet Ian Malcolm as he comes to visit John Hammond. She appears to be angry and cautious of her cousin, Peter Ludlow's, motives. When the InGen board of directors placed Ludlow in charge of the company she highly disagreed with Ludlow's ambition to create a new Jurassic Park in San Diego as a result of her first encounter with the dinosaurs four years ago on Isla Nublar. She along with Tim are also shown to be concerned with how their grandfather's (Hammond) doing. She does not appear again throughout the rest of the film and doesn't appear or is mentioned in the third movie.

Comic books
Lex and her brothers, now adults, are two of the primary characters in the comic book series Jurassic Park: Redemption.