Be careful on those types of ads nuguy.  You might get lucky on an ad like you describe and find a provider who is decent but your chances are not as good as seeing a well-reviewed provider with a website that gives you some more insurance that you will be getting what is advertised.

1. Check for reviews first- probably the best indication of how your encounter will go
2. Google search the provider's phone number.  If you see multiple listings under that number with different pix/names then chances are that the provider will a) not look like that b) not provide the services you expect c) all of the above
3.  You can always call the provider and try to get a sense of what they are like before you go.  Don't get explicit over the phone, but see if you can strike up a conversation to get a sense of what they will be like in person- rushed, English not so good, vague promises, etc.   Note that this step isn't fool-proof but it's another option for you.
4.  If you make it through the steps above and still decide to go, then you are officially TOFT (taking one for the team).   If you get there and the provider isn't what she advertised, then just leave.   If you decide to stay, make sure and write a review.

Good luck and stay safe.