Mystery Monday: In Laws

This is a photo of my husband's mother's father's brother and his family, plus what I believe are his wife's sisters.
The people from left to right are Duvillo Cooper Holly, Forrest Holly, Ruth Reed (née Holly) and Olive Holly (née Patterson). The ladies in black are the ones I believe are her sisters, or other relations, as they have very similar features. I think this picture was taken at Forrest and Olive's home. I have birth locations in Mississippi for Forrest and Ruth, so that is likely where they lived. The only date I have for Olive is her death on June 25, 1934. Any information about the other two ladies would be appreciated.