Like leaslie ann said there is a double edged sword on reviews ..Some have to have them to build their clientele up and on the hobbyist side you have to have recent reviews for some providers to see you..but once you have been verified and okayed a lot of people choose to be less active and not to leave as much information out there which is understandable.
Use the Mens board in each section and ask fellow members to send you a PM if they have seen a certain provider. If she is established like you say and has p411 and a twitter more than likely you can gather some info to assure you she is legit and even get an idea what some of her services are.
Reviews don't necessarily tell the whole story do a little research !
Don't depend on reviews only..Lot of people don't ever give bad reviews where their visit was not so good..Same goes for providers ask other providers about their experiences with someone..depending on reviews alone is not a smart thing..