When Sarah went into labour in the late 2000s, she was getting into bed when her waters broke, and quickly shouted after her husband. Sarah instructed him to phone Rianne Kilkenny, her midwife, and tell her that they'd meet her at St Helen's Hospital.
While Trys was driving her to the hospital in their Passat, Sarah spotted a group of people crouched in the road. Trys felt duty-bound to stop and check that everything was alright; though Sarah initially pleaded with him not to, she reluctantly let him go.
Sarah watched in horror as the quartet of zombies attacked Trystan. She bashed on the windscreen, shouting at him to get in the car as the zombies clawed and sank their teeth into him. He managed to open the door, but only succeeded in deflecting their attention onto her.
As the four zombies clawed at the windows of the Passat, an SUV pulled up behind and the occupants distracted the creatures away from the car, shooting them with handguns. One of them, Ianto Jones, talked Sarah out of the car, and safely hauled her and Trys into the back of the SUV, while the other went zombie-hunting in an adjacent construction site. Receiving a call from his friend, Jack Harkness, Ianto ran off into the construction site help Jack, leaving Sarah alone with her contractions growing more and more frequent.
Within the twenty minutes in which Ianto was gone, the SUV - containing Sarah and Trystan - was attacked by a second wave of zombies. Ianto and Jack had to shoot their way through upon their return, but Jack was knocked unconscious while attempting to load a captured zombie into the car boot. Ianto drove them all back the Torchwood Hub.
A makeshift bed was made up for Sarah in the Boardroom, where Ianto safely delivered her baby. She was then left to sleep with her son. Ianto and Jack left Sarah in the Hub while they went to St Helen's Hospital to visit Oscar Phillips.
Under the circumstances, Sarah hated being left alone. She was alarmed when Ianto suggested that he and Jack were going to "pop out" of the Hub for a while. She was caring; she truly loved Trystan and asked about him regularly when they were separated. She offered to finish breastfeeding when it made Ianto uncomfortable.