That's a possibility with any relationship and a risk you will always have to take. I understand you're situation is a bit unique considering her being a sex worker, but look at the fact she gave your money back, her personal number, and hung out with you as just two people enjoying each other. I don't think she would of did that if she wasn't really into you. You could even argue that you are special enough to take her attention over the other guy's she has been with.

As with any potential relationship, the worst that can happen is you are back to being single and not speaking with them again. I always go for it. The reward is always greater than the risk in my opinion. Goodluck with whatever you decide!