We know her. This is Mon Mothma, former senator and leader of the Rebel Alliance. She was the one who delivers the Rebel briefing about the second Death Star in 1983's Return of the Jedi, and she was portrayed then by Caroline Blakiston. (That's the one where "many Bothan spies died" to bring the Rebels information about the second Death Star.) Mothma was supposed to turn up briefly in 2005's Revenge of the Sith, played by Genevieve O’Reilly, but the scene was cut and she appeared only in a deleted scene on the DVD. But ... O'Reilly is back! A Lucasfilm source confirms that's her playing the character again in Rogue One -- and this time there's no chance of ending up on the cutting room floor.
