First, she wasn't some prostitute on the street. She was a model who did some nude modeling. I don't recall her ever having done sex work.

Second, like the other person says, it's because those jobs lack protections and support, and are looked down on by our society. Only the most desperate end up in those positions usually. The problems aren't cause by the sex work. Rather the sex work is done because they have problems, and the problems surrounding the job compound these issues.