Evaan plays it through night after night.
I go with the Scarif team to the planet and outsmart the Imperials, and somehow avert whatever the hell happened down there and the Death Star plans leave with Cassian's team and never pass through the Princess's hands at all.
I'm on the Tantive and we disguise me as the Princess and sneak her onto another ship, I lead the Imperials on a wild porg chase through the ship — for hours, she's fast and strong for someone her size but I'm faster and stronger — and she's far off when I finally get captured and they take me to Vader and he realizes he's been tricked, and I die alone in a torture cell but the Princess is already on Yavin briefing the Rebellion on how to blow up the Death Star.
I go to Scarif and infiltrate the imperials and find Tarkin and shoot him in the back of the head, and get killed instantly and never meet the Princess but the battle station is thrown into chaos and they never get to Alderaan before the Rebels blow them up.
She often sits awake while Leia sleeps. Leia's hair spills around her as she sleeps, hugging her pillow face down, often holding Evaan's hand in her sleep while Evaan stays sitting up against the backboard, holding a datapad she isn't reading. Sometimes she twitches and grips Evaan harder in the night, but she doesn't wake in the middle of the night, doesn't talk in her sleep or thrash around. Evaan is mystified by the soundness of the Princess's sleep, but forever grateful for it. Life has shown so few other mercies to her sovereign, her commander, her only love.
I stay on Alderaan instead of joining the Rebel navy, I stay in the Queen's mentorship program and I meet the Princess back then and I learn how to use the Force and we start communicating with it across the stars, and when she's captured on the Death Star she speaks to me through our connection and gives us enough warning time to evacuate the planet.
I'm on the Tantive instead of Captain Antilles and I outfly Vader himself and I get the Princess to Tattooine and the Empire eats our dust.
Evaan doesn't like lying down. She's just…generally not a fan. She keeps herself awake until she passes out, most nights. She knows it's bad for a pilot to be chronically underslept, but she's also never known a pilot who wasn't. Except maybe Luke Skywalker, farmboy looks like he's slept from dusk to dawn and eaten a hearty nutri-balanced breakfast every day of his life. No wonder he was the only one who could make the shot.
I stay on Alderaan and meet the Princess back then and we fix the culture in the Rebellion so everyone starts getting enough sleep, and all of our missions go better and more people join and we blow up the Death Star before they can even test-fire it.
Leia is curled up next to her right now, holding Evaan's left hand. She grips harder a couple times, spasmodically, and doesn't relax her grasp. Evaan puts her datapad aside and strokes the back of Leia's hand gently, until her death-grip loosens a little bit. The muscles around her eyes twitch but she stays sound asleep and silent.
They never talk about their dreams.