This lovely young woman in a white dress is wearing a straw hat decorated with some type of dark trim, most likely velvet. She is leaning her left hand on a dark lacy parasol and is resting her other arm on a fake column. She appears to have short hair although it is possible it is pulled back at the nape of her neck.
This cabinet card, while quite faded and peeling in places, still manages to show the beauty of this unidentified subject. I have actually enhanced the photo you are seeing here as it is even more faded in person. Additionally, it seems the unknown photographer did not take into account her white dress against the white brick wall and the photo was over-processed. I think he would have been more successful using a darker background. For example, check out this prior post showing a woman in a white dress: http://forgottenfacesandlongagoplaces.blogspot.com/2012/05/sentimental-sunday-women-with-hats-lady.html
I still love this photo as the subject has the most serene look on her face and is very captivating. Due to the thick gilt border I believe this photograph to have been taken in the late 1870's or very early 1880's.