This can be a difficult one properly ID, as she if frequently confused with a similarly-looking model. I believe her to be known as Nanette Shelton / Olga.
AKA's are Nikki Popoulis, (Fling Magazine 1978), and Nanette Shelter, try those and you'll get a couple hits...
The lookalike girl doc speaks of is Beth Berenson/Olga/Bertha...
They look very much alike, and both worked under the name Olga...
One way to tell them apart, Beth has a small mole in the area of her sternoclavicular joint, (whaddya think of that doc? :wave, and Nanette does not. But you can't see her neck in your photo, and with phototouching that can be unreliable as well...:glugglug: