This photograph was in the papers of Mary Kerr Motz (1917-2005). On the back is written "Marnie Kerr." Marnie was the nickname of Martha Frances Kerr Motz, the mother of Mary Kerr Motz. Which person is Marnie Kerr, if either, is unknown.
Possibilities: Adult is Marnie Kerr and child is Mary Kerr Motz; child is Marnie Kerr and adult is her mother, Eliza Catherine Yancey Kerr