How do I report provider no shows?  I can't report it in a review because I haven't seen her  LOL

Do I just post a message on a board?

Post it on the board of the providers region.

You should give her a call letting her know of your intentions.  Be a gentleman during that process.  She could have had good reasons for the no-show and may appreciate your call given that it would allow her to work things out with you.  The bad providers that have a no-show histories will ignore your forwarning, but the good ones that have a business to protect will not.