T H Taylor wrote:
I see no grey area here at all.
If she was hired for nude work then what she is supposed to be doing is... Getting her gear off and posing for you.  If she was nervous, she should have asked to bring an escort.
Bottom line:  You should have told her during the shoot that she was hired for nude work, not fashion, glamour or implied.  If she wants to be paid a nude rate, she should start acting like a pro nude model and do her job (or expect to be paid appropriately for the type of modeling she actually did i.e. "glamour.").

Need to save this one.  You're right on the money.  I certainly should also take a portion of the blame for the result for not putting my foot down and demanding the model to  step up to her obligation.  Hard (expensive) lesson learned.