A google search today reveals posts in other locations and "her" admitting she is a newbie.  Some posts also use the name "Susan" in addition to "Kelly".

Why I would not have taken a chance:

Law enforcement sometimes tries to show it has a sense of humor via the names selected for their "operations".

I would not put it past a department to decide to photograph a female in what appears to be a courthouse or the public area of a jail, thinking it would be very humorous if some guys "took the bait".

The fact that she is in street clothes could also be a red flag.  Three decades ago local police would put a female decoy cop in street clothes and have her walk El Cajon Blvd as bait. "Johns" who "hit on her" and got arrested had the additional disadvantage at trial of testimony that they were soliciting a female dressed as any "normal" woman on the street would be.  It would demonstrate that (street) prostitution is not a "victimless" crime.

Perhaps her recent ad saying she is a "newbie" indicates that she was clueless how her first photo might be construed.

If anybody takes a chance on her, suggest she read this thread.