talk to her first in some way.  Ask her if she will be a reference for you.  Just because you think you were a good client doesn't mean she feels the same.
When she replies, you can figure out how to use her as a ref.

Swim

I saw my first provider last week through an agency. I did everything by the book and I think (think) I was a good client.  the provider is traveling, and who knows when/ if she will ever be back.

in terms of references, would I just provide the agency's contact info and the name of the provider? would she have given the agency the rundown of my desirability as a client?

thanks in advance.

Many indies will not accept agenices as a reference and many will not accept ter white lists refs as well. Just remember the ladies all screen differently. Many escorts want to speak with the lady you give as a reference.  Also for future reference, it's a good idea to give the lady you're using as a reference a heads up, that you are doing so.