Deborah was a 20th century human.
She, Vince and some Mods and Rockers were transported by a Maker from 1965 Earth to an asteroid in the late 30th century. Their son Davey was born on the asteroid. Needing to survive, they had to choose a side to ally with and picked the Mods. Davey was killed during a fight with the Rockers in 3012.
By that time, the Makers realised taking the people from Earth was a mistake. They offered to let the people remain in the 31st century, or return to their original time which would undo everything that had happened to that individual. This would cause them to have no memory of the prior 19 years. Davey's parents chose to return, as Deborah would be pregnant again and Davey could be reborn. (PROSE: The Space Age)