Dorothy "Ace" McShane

Ace was a companion of the Seventh Doctor. Her real name was either Dorothy Gale or Dorothy Gale McShane. Initially a brash and reckless teenager, Ace matured significantly into a strong, independent adult over her many years of TARDIS travel and other experiences, who was capable of surviving on her own. Born on Earth, Ace was a central player in fighting the return of Fenric and battled many of the Doctor's most infamous foes alongside him, including the Daleks, the Cybermen, and the Master. Her timeline was complicated; during an encounter with the Quantum Anvil, she saw her future fracture into various different but all valid possible outcomes. Amongst these futures were continued travels with the Doctor, a life in 1887 France, and becoming a Time Lord after attending the Academy on Gallifrey. Within that version of her future, she was given a TARDIS of her own and she became an agent of the Celestial Intervention Agency. Eventually, due partially to the erupting Time War, Ace had her memory erased by Irving Braxiatel, who also further meddled with her personal history. She was returned to Earth, where she set up a charity - A Charitable Earth - dedicated to helping Orphans.