Who do you think you are booking Kate Moss?
What are you going to do if she does not complete her work, sue her?
Or maybe not pay her for anything like some shooters have been known to do.
Pay her by the day or the set and be thankful that she still wants ot work for you in a weeks time.
Or better still learn to drive a taxi, cos you sure are going to be lost being a photographer shoting porn.