I did try to google myself and there is very little information on me, certainly not the very personal items she came up with.
Nice try.
What kind of questions did she ask, and what were your answers to those questions. I am going to assume the questions she asked were very open and she just narrowed the search down. It's like when you do a search in any search engine: you can be very broad with your query, and then click the advanced button and narrow the search down until you reach the hit you were looking for.
She probably had caller-ID, so she knew where you were calling from. With that information alone there are sites out there that reverse search the phone number to see where it's coming from. With that information (and depending how the backsearch site is designed) your full name will be available. From there she could've gone to a site like beenverfied or something and do a search on you to get more information. It's really not that hard to do, and it can be done in a matter of seconds if she has a group of people working with her.
I mean, if I didn't finding it morally wrong and unethical I could probably dox you right here. Of course, I would only get your name, location, some private info like your SSN, DOB, husbands name, etc. Then I could just trick you into revealing more information, then you'd think I'm some kind of medium too.
For example, just go to this site and do a quick search on your phone number:
http://www.spokeo.com/You will be very surprised, and you weren't using all the tools that are on the internet.
And you say she had nothing but your first. So then, you did appear on her caller ID and she just claimed to have not known your last name. What kind of medium wouldn't know
all there is about the caller right when he or she calls? She probably wasn't really good. If anything she would know your last name also (if she was any good, I mean).
What kind of questions did she ask? What were your responses to those questions?
EDIT: And you talk about a small amount she charged verse her effort to use resources. I don't know how much she charged so I will just round the number to 10 because it's easy. Say she charges 10 dollars per call and a reverse search site charges 1 dollars, she's making off with 9 dollars from you. If you talk to her for an hour, then she takes another call for an hour she's earning 81 bucks a day. Sites that know our information don't cost that much for a subscription, so in the end she's walking away with a profit deceiving others based on those sites finds. A simple google search wont reveal too much; but there are thousands of sites out there that will reveal your information.
From a security standpoint it's called
social engineering . Be careful next time.