If she's not newbie friendly, that could be why she's not responding to you... or, it could be because of the holidays... a lot of ladies were gone w/family, and not checking e-mails. If you don't hear back from her this week, it's probably the newbie thing.

Might be because you're new.
She might be on vacation.
She might not be into planning things too far ahead.
She might be a flake.

At this point, to avoid having her get all bent out of shape and consider you're 'pestering' her, keep shopping and find another one. Get a few under your belt (pun intended) then contact later.

You are looking for a pay4play date, not a GF.  Do not obcess over any one girl.  
I don't see any "wrong" thing that you have done.  She might be away, home for the Holidays, etc.  You can try again when you can set a date with a week or so.  I often topic my inquiries with "Advance Screening".  Often once the screening is complete, the date ends up getting moved up if there's an opportunity.
Have a couple of others in mind and try screening with them as well.  
It's really a bad idea to serial date a single provider...  The emotions can be very powerful.  It's hormonal...  I try to rotate a few favorites, so easier to keep my perspective.
It's ok to circle back for the one you wont but don't be a pest or seem despirate.  If you look like a stalker, she'll avoid you like the plague.
skb

In the meantime..

I would suggest signing up for one of the verification sites.Depending on what area you are in some are more widely used than others.I would also suggest contacting other ladies because you never know why she is not responding.It could be an array of reasons make sure you read the lady's requirements on her website or ads on what is needed to set up an appointment.As long as you are polite and provide the required info a lady should get back to you.
But,if you just provide for an example "Hi I am John email [email protected] I am interested in seeing you in Jan." with some ladies you will not get a response with minimal info.Provide all info required in the initial email so that cuts down time on your part and the lady.
Not saying that is what you did but you did state that you provided your first name and email which is not a lot of info to begin with.Nothing worse than having to go back and forth with a gentleman about what is required to set up an appointment which is stated on most ladies websites just to have the gentleman not respond to the request for additional info.
Good luck!

give a specific day/time within a week or two, you will usually get a response to an e-mail.  Most ladies do not plan their schedules more than 2 or 3 weeks ahead unless they are touring.

My apologies if I am reading what you said incorrectly, but it seems to me that the reason she may not be responding is that you are not providing her with adequate screening info.  You stated that in your first note to her that you provided her with your e-mail address and first name.  That's all?  If that's correct, not surprised that she didn't respond.   As for your second note, it seems that you corrected the information shortage, but if that was sent within the past week, she may be busy with the holidays, and not checking e-mails.  You might be patient for awhile longer, then move on.  Don't waste the time contacting her a third time...if she's interested, she'll get back to you eventually.

Had this been me, I would have provided my full name, age, race, occupation, maybe even height and weight, as well as a specific date, time, and length of session desired in my initial contact.  Or I would complete the form on her website if she has one.  Almost always, this generates a quick response.  

It also helps to be a member of a verification service as a newbie, until you have references or are comfortable with providing her with employment info for screening if she requires that.  Lack of references is a drawback, but good providers have other ways to screen when they encounter this.  Good luck!