We are starting a little mystery tour with this lovely little girl, identified as Mary Harding. If you haven’t already guessed, Mary Harding is an incredibly common name, with Mary having been the #1 most popular girls name for much of the last two decades of the 19th century. I believe this is at minimum an 1895+ cabinet card due to the fancy embossing. It’s a floral pattern that I have seen one other time on some square snapshot type photos I found. This is definitely a studio photograph, but the name of the photographer was not present on the back. My suspicion leads me to think this is really a post 1900 photo.
Tomorrow, someone else identified in the same handwriting as Mary.