kronii didn't finish college, she said before (don't remember if it was a stream or a twitter space) that she still needs to go back and finish her career, on the joker watchalong she talked a tiny bit about what she studies, something about wanting to help others.
yeah i doubt kronii's family is well off considering she gives them most of what she earns, so that's probably why she didn't finish studying, and i remember her saying she was working on an office but i don't remember if she explicitly said what she did.