Moira is the eldest daughter of STARS veteran, Barry Burton. In Resident Evil: Revelations 2, Moira and her TerraSave co-workers including Claire Redfield are captured and taken to an abandoned prison facility supervised by Alex Wesker.
Moira is a secondary character in Claire's portion of the game. She refuses to use firearms after accidentally wounding her sister with a handgun as a child. Instead, Moira uses tools, such as crowbars, to break open boxes and to attack enemies. She is estranged from her father.
Eventually while fighting a mutated Neil Fisher, who betrayed the Terra Save group, Moira overcomes her fear of using a gun in order to save Claire if the player selects this option, which is canon. Moira is separated from Claire and saved by Evgeny, a Russian man who later chooses death once his daughter is dead.
Moira then returns to save her father and friends from Alex Wesker, who is now fully mutated.