That's 'granny' Sarah sitting next to her husband Onyango, the young girl standing is their daughter Zeituni, born in 1952. In 1964 she would have been 12 or so. Kezia isn't in the photo.
Omar was already in Boston, Zeituni went to live with the Kenyan and Ruth in Nairobi, 'Jane' we have no idea, Yusuf is the brother with whom he attended school at Maseno where Yusuf was known as Joseph and Sayid still lives in the village as 'granny' Sarah's shadow.