Stacy Townsend

Stacy Townsend traveled with the Doctor and, later, Ssard, the Ice Warrior, who she would later marry.

Biography
Stacy was born in 2220. By 2246, she had gotten engaged to a man named Bill at St. Christopher's in Norfolk. They both worked on a deep space haulage freighter, the Dreadnought, which the Cybermen came to attack. The Cybermen subjected Bill to cyber-conversion. By the time the Doctor arrived in his TARDIS in response to the Dreadnought's distress signal, he could not save Bill, so she decided to join the Doctor on his travels. (RT: Dreadnought)

The TARDIS then materialised on the planet Mars in 3998 where the Doctor and Stacy found themselves caught up in Ice Warrior infighting and politics. met an Ice Warrior named Ssard, who, after an adventure with the Doctor and Stacy subsequently also joined them on their trip. (RT: Ascendance, Descendance)

Eventually, Stacy and Ssard would leave the TARDIS and decided to live in Ssard's time period. The Doctor was invited to attend their wedding, which took place on Micawber’s World in 3999. (EDA: Placebo Effect)