I'm in no way saying that Casey had an actual job but when I heard the term "work bag", I immediately thought of the work bag a stripper would have(mix cds, bathing suit, dresses, shoes, makeup) or escort(fetish items, condoms, etc).
Since noone seems to know what she did with her days and escort agencies were among the searched items on her computer...my mind tends to go there. There is the argument that she'd have money hand over fist if she did either of those things, but not if she did them half-heartedly, here and there.
I think dancing may have been "too much work" but answering a craigslist ad and hooking up might have been right up her alley. Fast money spends just as fast, especially if she did it once or twice, then decided stealing was wayyy easier, and she was better at it, so stick with what you know. Just my two cents about the term "work bag".