Being both Asian and A Nerdy girl, I can only put myself in CJ's shoes to try to figure out what she did before SHTF.
I fell in love with CJ's character after Saul and Vic delighted in her " How to Manuals." I create my own how to manuals for work and home. I also know how to prepare for a bugout...and guess what I do for a living? I'm a medical coder. We must not assume that a person's talents can only be job based. I'm pretty sure that since she's Chinese, she's an over achiever, attentive to detail, and is constantly prepared. If her parents were anything like mine, she was taught to survive at an early age, encouraged to learn everything she could. No play time...always study, learn, research time. I don't have a Katana but I do have throwing stars and knives. I don't have a gun. She's Chinese, so it's safe to say she isn't a Nurse..that's a field that's dominated by Filipinos. She could be an architect or an engineer because she knows how to fortify a stronghold. But then again, she could be a medical coder like me, that likes to read and had a father that was an engineer.