Leia has already appeared on Star Wars Rebels, so she was definitely part of the Rebel Alliance long before the events of A New Hope. And because of her capture at the beginning of that film, we know she was directly involved in the plans to steal the Death Star's blueprints. Given her role in the very first Star Wars film, and her prominent position within the Rebel Alliance at that time, it would make a lot of sense to see Leia in command of a Rebel control centre, helping to organise the attack. While you couldn't have Carrie Fisher come back and play the same age she did 40 years ago, you could cast someone else in the role, and there's a ready-made candidate already in the Star Wars universe: Billie Lourd, her daughter, who had a cameo in The Force Awakens.
NCTJ-qualified journalist. Most definitely not a racing driver. Drink too much tea; eat too much peanut butter; watch too much TV. Sadly only the latter paying off so far.
A mix of wise-old man in a young man's body with a child-like wonder about him and a great otherworldly sensibility.