It's the world's oldest profession (oldest JOB?) and while it's not for me, I refuse to judge those who decide to become sex workers.
It may be illegal here, but it isn't in many other western societies, where sex workers have been brought into the fold so they can be protected, work in safe environment and be taxed. My sister works in the sex industry so I have some experience with it.
Many many sex workers are exploited, abused and/or are simply desperate to fund drug/alcohol habit dependancy & have emotional issues.
Then again there are many other perfectly healthy and sound of mind women who choose to be sex workers - any why shouldn't they. Though all that I have met have gone into it, not through a life ambition to be a hooker, but as a way of getting themselves out of a tight spot/financial issues.
If she proceeds she must keep her wits about her, takes all the necessary precautions re her health and safety in her work and has an exit plan. It's a job that probably has a higher emotional and physical toll than others, not to mention what she will be exposed to will more than likely put her off men for life. And her trade will depend on her presenting herself, indeed treating herself as a sex object - which may be difficult to sustain & may affect they way she thinks about herself.
I do think at 19 she is being naieve to think that this is a career she will want to be doing as an older woman. Indeed most people these days are not doing the same work at 50 that they were at 19. As for staying with the same agency for years and years - again this is unlikely to happen.
Another problem for sex workers is when they want to move on - they feel ashamed about putting sex worker on their CV etc - so it can cause problems getting out of it & into a 'straighter' life.