Officially, I don't know. But test her with everything, people, names, faces, dates, objects. If she can remember everything she's ever read, then yes, pretty much, photographic memory.
Photographic memories or extremely rare, many professionals in fact believe that they don't exist. Those that do believe say that children are the most common to have them. As far as I am aware there is not an official test. A person with a photographic can recall every detail of what they have seen.