Sarah Clark was engaged to Stuart Hoskins and a close friend of Jackie Tyler.
Stuart first met Sarah on a street corner outside the Beatbox Club at 2am. Sarah didn't have money for a taxi and Stuart took her home. He gave her his telephone number by writing it on the back of her hand. According to Stuart, he "[n]ever got rid of her since." Sarah fell pregnant with Stuart's child out of wedlock and they got engaged.
When she arrived at the church for their wedding on 7 November 1987, Sarah was confronted by a Reaper; though she screamed in horror, it ignored her for some reason and attacked and devoured the vicar instead. She took refuge in the church, as did Stuart and their guests. She begged the Ninth Doctor to save everyone trapped in the church. After the Reapers vanished, they were married. Along with everyone else in the church, Sarah forgot about the Doctor and the unusual events that happened. The only unusual thing she remembered was the death of Peter Tyler just outside the church. (TV: Father's Day)