They're Ray-Ban Wayfarer in Tortoise. You can get them at
http://www.shopbop.com/wayfarer-sun...02094311&extid=affprg-3154566-RAYBN2000014733
They look like Wayfarers to me...they even have the little silver horizontal line in the corners.
She could have gotten customized/prescription lenses and thats why they don't have the "Ray-Ban" marking on them.