There is no identifying information for the woman photographed in the CDV. The photographer's imprint on the back reads: “Q. P. Knight, Photographer, Batavia, New York.”
I located a Q P Knight, photographer, living in Batavia, Genesee, New York in the 1880 census.  A Google search turned up a family tree that showed the same individual, with a full name of Quartus Parsons Knight.  According to this source, Quartus died in 1894.
1. 1880 U.S. census population schedule, Batavia, Genesee County, New York, enumeration district (ED) 4, p. 20, dwelling 170, family 189, Emily Thral; digital images, Ancestry (www.ancestry.com : accessed 4 April 2011); citing National Archives and Records Administration microfilm T9, roll 835.
2. Descendents of Richard and Sarah Rogers Knight