Dr. Carlyn Williamson was an anesthesiologist and part of the seven-man scientific team aboard the United Systems Military vessel USM Auriga that successfully cloned Ellen Ripley in order to recreate the Xenomorph species.
Williamson was one of the few people who managed to escape the Auriga aboard an escape pod during the initial stages of the Xenomorph outbreak.
Williamson was present when the Queen embryo was surgically removed from Ripley 8, and it was her who removed the infant Xenomorph from the room following the successful operation. After Ripley 8 regained consciousness while Dr. Sprague was closing her incisions, attacking him and badly breaking his arm, Williamson assisted in the surgery to repair the damage. She later took part in the studies of Ripley 8, notably testing her inherited genetic intelligence, including her ability to speak and even remember events from Ellen Ripley's life.
When the Betty arrived, Williamson observed as Larry Purvis and the other kidnapped civilians were implanted with Chestbursters; she was physically sick after witnessing the event. Along with Dr. Gediman, Williamson witnessed the Cloned Xenomorphs' eventual escape from captivity (and watched as they subsequently captured Gediman). Following this, she was one of the few people who managed to successfully evacuate the ship aboard the first escape pod.
- While Williamson escapes the Auriga in the film (she is visible very briefly aboard the first escape pod before it launches), in the novelization, the survivors find Williamson dead alongside several other scientists in a small Hive built by the Xenomorphs in a laboratory adjacent to the one where Ripley 8 was incubated, their chests torn open by Chestbursters.