I agree this is a highly irresponsible photo choice. Can you imagine the humiliation this would cause to the young girl in this picture if she knew she was now a symbol of child prostitution?
Your use of this photo, that you took without permission, is unconscionable. It plays into regressive attitudes about young women and their clothing, for instance: "she looks slutty" or "look what she's wearing, she deserves it"
It's true that publications on child trafficking rarely if ever contain images of the actual victims - for good reason. However, I am horrified that instead of just concentrating on the journalism -- have you checked out Human Rights Watch lately? -- a publication and it's contributing photographer would choose to display images of ramdom young women that have been determined - by you - to look like hookers.
In a story about young victims, you have managed to victimize someone. Congrats. I hope you get sued.