My first problem is the word I put in brackets - I've found the "once a marine, always a marine" saying in different places, so it would be correct for another character to refer to her as a marine, using the present tense, not an 'ex-marine', right? Or would I be overdoing it?
Secondly, what would she be using as slang for the plane she's piloting? I want her to say something like "who’s going to try to get the drop on me, in my own . . ." - what? I found 'helo' for helicopter, but she flies fixed-wing aircraft. Also, I wanted something to show a sense of possessiveness - it may just be the company jet, but while she's flying it, it's kind of hers.
Also, would a Marine use a phrase like "get the drop on me"?
Finally, I've looked for battle cries, and found 'get some' and 'Oorah' - is that real or just movies and tv (online sources sometimes contradict each other)?
My search terms were "US marine slang", "US marine slang plane".
ETA: Thanks for all your help, I've got enough to work with here!