The previous owner of this cabinet card describes the subject of this cabinet card photograph as being a “young woman devoted to spinsterhood”. The woman is further described as having a “butter wouldn’t melt expression”. This bespectacled young lady is dressed in all-white and is holding a white parasol. Her hat has feathers and seems to be preparing for flight. The photographer of this image is J. S. Fritz. The cabinet card gallery has a large collection of his photographs and to view them and to learn more about Mr. Fritz, click on the category “Photographer: Fritz (JS)”. SOLD
THE CABINET CARD GALLERY 
When you take a closer look at the pic, you notice that she is younger than she first appears– not yet an adult, because of the shortness of her skirt (for a girl rather than a woman). Perhaps 12 or 13, but a future librarian in the making.
Great observation. You are correct. The young woman in white is more likely a young teenager in white. She is wearing quite a fancy dress. Fancier than most thirteen year olds appearing in cabinet card photographs. Perhaps she is from a wealthy family?
This is most certainly a young female, but I think older than 12, or 13. Has anyone noticed that she is wearing a ring on her left hand. So perhaps she is a young married woman, and not a “spinster” after all! Yes, a member of a wealthy family, most likely too.