I agree with the post from maryrenna that this is a three generation photo. Son and daughter of the parents on either each end of the picture and the young girl is the granddaughter. Facial characteristics between the son and father, especially the ears is striking. The son has a more direct pose to the photographer than the father, but you can still see the same shape. The eyes and nose of the grandmother and her daughter are very similar. As others have said the hand wrapped around the arm could very well indicate mother daughter as the facial characteristics again are similar. It may be the son-in-law is deceased or just not present for the photo.