Hi Jan,
I just saw your post from almost 10 years ago. I am researching my great great grandfather, Frank Skinner. He was born in New York around 1821, and married Catherine Adelma Beardsley in 1860. The family had a daughter, Georgia, in NY, then moved to Ohio and had a son Ernest who was four years younger than Georgia in 1866. My understanding is that they moved to Illinois briefly after 1870. So the picture sounds like it could be them. The girl in the picture would have been around 9 - 10 years old and the boy about five years old. Did you ever find out more about the picture?
Thanks,
Dave