Alexis "Lex" Murphy is John Hammond's granddaughter and Tim's sister, who accompanied the endorsement team on the tour as a gift due to her parents getting a divorce. Her novel and film version are very different, with a number of her traits being given to her brother and vice-versa. Being John Hammond's granddaughter, she is second-generation Scottish-American.
Alexis Murphy is first seen in the novel coming out of a helicopter with her older 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, though in the film he seems to not mind it at all. 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.
She is portrayed as an extremely whiny, irritating, unpleasant little girl with a love of sports. She hates dinosaurs and teases Tim about his fascination for them in the same way that their father does. Due to all of this, she nearly gets herself and others killed multiple times yet displays no change in character.
Unfortunately, Dennis Nedry took the 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 cafeteria while he worked with the other adults. The kitchen was 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.
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, while Lex retains her whiny nature and unpleasant disposition. She is distinguished by a tank top decorated with multicolored spiral shapes and trousers and a blue baseball cap. She is portrayed by Ariana Richards, who was 12 years old at that time.
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, much more so than the dinosaurs.
She is shown to be rather indifferent towards the dinosaurs, which eventually turns into hate and fear of them after her and her brother's encounter with the T. rex in the Explorer. Despite being the older sibling, Lex is much faster to panic and prone to fits of hysteria, ultimately endangering their lives when she alerts the T. rex to their presence. She turns out to be easily intimidated and does not enjoy being very close to dinosaurs, unlike her brother, who proves to be the more collected between them.
Lex has very good computer skills and is a proficient computer hacker. She was able to get Jurassic Park back online and the phones and the locks working again. 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, though he learns to warm up to her over the course of their survival in the Park. Lex is last seen sleeping against Grant's side as the group escapes Isla Nublar by helicopter.
Lex is not mentioned by name in the sequel but it is stated that she is in prep school.
An older Lex and Tim briefly meet the disgraced Ian Malcolm as he comes to visit John Hammond in New York. She and Tim are shown to be concerned with grandfather's rapidly declining health, as well as the hostile takeover of InGen by Hammond's nephew Peter Ludlow.
Lex has not appeared in any films following the second film.
GamesLEGO Jurassic World. In the game, she has four abilities. Like most female characters in the game she possesses the Agile ability, allowing her to leap higher than male characters and can use special pink/blue objects to access new areas. Her Hacker ability allows her to access computer terminals to manipulate objects and in the game's retelling of the events of the 1st film, she uses this ability to restore power to the park. She also has the unique ability to throw baseballs as a ranged weapon which she can use to hit LEGO bulls-eye target, switches, or enemies. Using her Scream ability she can shatter LEGO glass by screaming loudly. She has two playable costumes, her initial outfit and baseball cap from the beginning of the first film and her "Survivor" outfit (her cap-less damaged and dirty outfit) from the end of the first film. Her standard character model and voice is also used as the default for the customizable character slot, Custom C. Interestingly despite Lex's cap appearing on the default of Custom slot C, it disappears if the slot is customized as her cap (complete with hair) does not appear as a customization option.
Lex and her brother, now adults, are two of the primary characters in the comic book series Jurassic Park: Redemption. Lex' vegetarianism from the first film is extrapolated. Lex is now the CEO of LexxCrop, a company that produces organic crops. Lex's dislike of dinosaurs have only grown worse since the events of the park disaster, referring to them as the most savage and dangerous creatures on the planet.
Lex and her brother appear in the manga Jurassic Park.