Mrax by Layla Nash

Earther and alien.
Love and logic.
Fire and… thermite.
Rowan MacLeod is tough as nails. Life was hard on Earth, but she’s determined to let nothing hold her back… even after ending up on a rusty bucket of a spaceship surrounded by barbarian aliens. A special mission to resurrect old fighter craft for the rebels is her best chance to prove herself… until disaster finds her again.
As the medic on the Galaxos, Mrax has to be quick on his feet. He doesn’t have time for anything else, especially a feisty Earther female. Until the intelligent and beautiful Rowan ends up in his sickbay. She’s everything he doesn’t need complicating his life. But she’s everything he wants.
When a hostile alien team lures Rowan into danger, Mrax will do whatever it takes to save her. Even if he ends up needing a little saving himself.
Rowan and Mrax have one job: build a fleet to save the rebellion. Any distractions could jeopardize the whole universe, even if the force of their attraction is stronger than gravity itself.
But sometimes, even when it doesn’t add up, love comes out on top. Now they just have to make sure the rebellion does, too.