"She told me she wanted to quit, but won't even try to get a regular job."
"She keeps saying she likes it, but I know she must hate it."
"She said what she does is none of my business and to stop talking about it."
When I meet members of the community who know an adult involved in the sex industry, they are often frustrated that their attempts to 'help' are refused or ignored. It's easy to let our personal feelings get in the way in situations like these, but if we really want to help, we have to consider a few things.
How did you find out your friend is involved?
If they told you themselves, they probably believed it was safe to do so. Are you respecting their boundaries? If you saw their ad online, or saw them walking the streets, they may not have wanted you to know. Did you confront them, or tell other people you saw them? It is very important to remember that no one appreciates having their boundaries pushed, even by well-meaning people. Be kind, and be respectful of their privacy.
Are you allowing them to define their experiences?
If the person you care about says they enjoy (or don't enjoy) sex work, it isn't your place to 'correct' them. Don't insist they are a 'victim' or 'empowered.' Let them lead the conversation and use whatever labels (if any) they see fit. Their experience is their own, and it is valid, even if you don't like it.
By the same token, if they have been assaulted or harmed in some way, don't pressure them to report the crime(s), or tell them what you would have done in a similar situation. Neither are helpful, and can be traumatizing unto themselves.
Are you asking the right questions?
Instead of asking, "Why don't you just quit?" or "How can you do this to yourself?" consider asking, "What made you feel like this is the best choice for you?"
Are you listening to their answers?
It's easy for average people with no experience in or near the sex industry to assume that sex work is the biggest problem in someone's life. Don't do this. LISTEN. If they say, "I'm depressed and want counseling," and you answer, "You're depressed because you're a sex worker," you're telling them that they don't know what's best for themselves. This is a surefire way to shut down all communication.
Have you considered the obstacles they are facing?
Maybe they are ready to leave, but have a long history of arrests for prostitution that you are unaware of, and can't find a job. Maybe they were hired, but the boss is harrassing them. Berating them, giving the bootstraps speech, and accusing them of 'not trying hard enough' achieves nothing. Consider the notion that you may not know the whole story.
Have you let them down in the past?
Have you offered your friend a place to sleep should they ever leave the life, only to refuse them when they try to accept the offer? Have you violated their privacy? Have you asked them invasive questions about the sex work they have done? If they 'relapsed' after quitting the life, did you become exasperated or angry? If you answered yes to any of these, your friend may not consider you reliable or trustworthy. Don't make promises you can't or won't keep.
So...what should you do?
I may sound like a broken record, but the best things you can do are to listen without judgment, be empathetic, and treat them like capable adults. When they are ready, they will know they have a friend in you.