Mary lives in a house in London with Jack. An Anomaly to the Early Cretaceous opened in the house while they slept, letting through a baby Kaprosuchus. She awoke during the course of the night to hear noises caused by the Kaprosuchus. Unable to awaken Jack, despite her rigorously shaking him, she grabbed a golf club and went downstairs to investigate the source of the commotion. She ended up finding the Kaprosuchus on a chair under her dining room table. She was obviously surprised by the appearance of the creature, and attempted to touch it, but withdrew her finger when the Kaprosuchus snapped at her. She managed to hit it with the golf club, and took it to the bathroom, holding it by its tail. She subsequently flushed the young Kaprosuchus down the toilet. (Episode 4.2)
- Mary is never named in Primeval, only in the Episode 4.2 credits.