you do owe her the full amount for the time she set aside.

The most tactful way of going about resolving this is to ask her what she wants.  By being upfront like that she might accept half or even less, but don't count on it.

We all have encounter traffic, delays, gps issues etc however, because she wasn't late but you were and she allocated that time to see you, the right thing to do is give her the full amount because is out of her control what happened to you. Some ladies incur in expenses when scheduling dates ( hotels, drivers, babysitters etc). In reality, I feel that the entire amount should be honored to her because she was readily available to see you. Don't be surprised if she does not want to see you again unless you plan to compensate her for the time she missed. Some gentlemen try to leave their place way ahead of time in case this happens so they give themselves enough time to juggle with unexpected situations.

A major local weather event happened when I was enroute & I was forced to cancel.  I now plan to be there 15-20 minutes ahead of the time & find the correct location & I withdraw to the corner coffee shop as hanging around a hotel lot without going in promptly is not discreet.  In many cases, I can see the location from the coffee shop so is only 5 minutes to return.  
I also went to the wrong hotel once...  2 hotels different versions with same chain within a half mile of each other.  I figured it out but cost me time with her.  We did get a session in.
What to do about a last minute cancellation varies.  Some gals have not asked for a payment while others may expect it.  In my area, 1 hour of FBSM can be had for 100 or a bit more.  I think that 50 would be adequate & express your sincerity.  
In the first case, I rebooked a couple of days later & we had a great time & I still see her when I can.

You did the right thing in telling her what happened & I hope apologizing.  Just taking the hit for the mistake should count for something.

-- Modified on 12/27/2013 9:19:00 PM

the provider should be given the full amount since the delay was yours.

Sorry, but shit happens.

We are all humans, so we make mistakes.  When I used to have my own escort agency I would tell the guys who canceled to give the lady $60 at the door for her time, and everyone was happy.  

I suggest next time you decide to book an appointment to be completely honest with the provider in regards to your medical conditions prior to booking, so they can make a choice.  Some providers state on their website handicap, and disabled friendly.  I do!  I know for a fact people who have medical conditions require more patience.  On my website for booking I ask the clients if they have a medical condition.  A good provider will block off extra time to accommodate your needs.  I personally would never book back to back, but most providers due & that is a fact.

Find a well reviewed provider who is known for respecting your time because caca does happen.  I had 1 guy who was an hour late & he did not tip me, or take responsibility for not doing his homework prior to.  I hate waiting around in lingerie for a late appointment.  I believe you should google directions prior to & double, triple check.  If you need help getting to the ladies location call to communicate because chances are she will be able to help guide you there.

Best of luck to you!