Okay, the idea I'm leaning towards is a little wiggy, and may or may not really be appropriate for the game style. In particular, the character may not have much to "do" on the ship, which could be a problem, or not, depending on where we focus action on.
In a nutshell, you could think of this character as being a sort of cross of Kaylee and Simon...that is a character who has a sort of intuitive/instinctive grasp of medicine and science. Someone who's smart, but largely self-educated via whatever references could be accessed and simple experience.
Got any suggestions for such an idea?