Kate and Clara Key

There are two little girls in their Sunday best dresses, socks or hose, and shoes. They may be between 5 and 8 years old, but I am not good at guessing ages. The older one has a big bow in her hair. Written on the back is "Kate and Clara Key". There is no date and no mention of a place. Second photo of the same children with an older couple who may be the children's grandparents.

Do you recognize Kate and Clara Key? They are unknown to me.