The scan does not do the original justice. An amazingly beautifully preserved CDV of a Barnum performer. She was originally from Kokomo, Indiana. Hired in 1879 at age 11, she weighed 28 lbs. The photo is then most likely also from that year or within a year or two after that date.
For more information, check out quasi-modo.net
dcphotoartist 
Since the card says age 12, wouldn’t you assume it is from 1880?
Actually, with Nellie, you can’t assume anything, because her age was frequently mis-stated both up and down, for publicity purposes.