Lucky, I recall reading that story from another news agency in another thread somewhere in the last month. CNN distorts and exaggerates on many stories, so I would not be surprised if that one is false as well. The street they are likely referring to is what is called "the alley" behind Adelitas. There are other streets the street girls stand on, but that one street is between several clubs and is probably the one they mean.
The best arguments I saw about it is that the cops patrol those streets regularly and check the ID's of the girls working there. The girls working there are also required to get regular health checks and have a card with that info. The cops surely would pick up any girls not meeting the minimum age requirement, and the other girls there would probably rat out any underage girls since they would be their competition. If you go looking for it, you will be thrown into jail without ever finding it.
Before going, you might want to read up on TJ at this website or at tjamigos.com before going. Don't believe the news agencies like CNN who have an agenda.