The new rules have relaxed to the point where if "money changes hands" a review is allowed even if no meeting ever occurred.

NCNS, (unless she ripped you off with an advance payment) time wasters, flakes etc are not allowed to be reviewed, but you are free (and encouraged) to warn your community by making a post calling out bad behavior on your regional board.

Only a rip-off report (review score of 1 out of 10)  is allowed if you don't actually meet her.  If you didn't pay and she ghost's you on the room number is not reviewable.  Waiting in your car and deciding to leave if you haven't paid her yet doesn't qualify either.  Your regional board is the place to report to your fellow mongers what went wrong to cause the meeting not to take place.  

 
If you show up at the location, you meet her and realize the one-eyed hunchback dwarf with a wooden leg that greeted you is not the girl in the photos you relied on, you are entitled to a review whether you're five minute in or 30 minutes in.  You met her and that meets the basic requirement.  

Kind of gives providers a lot of room to simply ghost you once you’re at the location, which is the equivalent of a no show/time waster for them.

I got ghosted by a provider 2× in a row so I posted that she had done so on my area board. That's better because even non members can be warned about time wasters. I hot a DM from longtime hobbyist that this provider had been mentioned as doing this on other hobby boards. This is unfortunate as I thought this girl had her act together.