Ms Randrianasolo was a psychic and part of the crew of the Tisiphone. She grew up in Madagascar.
When the Tisiphone went through a wormhole in the 26th century and arrived at 20th century Earth, the crew settled in England. Over time, Isaac Summerfield II created a kind of underground railroad to help stranded aliens off the planet. By the time the Seventh Doctor met the group, the only crewmember from the Tisiphone remaining was Ms Randrianasolo.
Isaac wanted to start a nuclear war to keep the world on a military footing so they would be better able to fight the 22nd century Dalek invasion. After his plan was stopped by the Doctor, Ms Randrianasolo left to join a peace camp, feeling she could no longer trust Isaac. (PROSE: Return of the Living Dad)