Schwencke Family photo found

Found a pictures of dad's side of the family, although I don't know who some of these people are.  From the right to left, I think I can identify my dad, Herbert Russell Schwencke, mom (Rebecca Jo Vahalik Schwencke), my grandpa (Bruno W. Schwencke).  On the back of the picture dad had written in pencil Uncle Bob Russell and Aunt Lucille. The dark headed woman to the left of grandpa looks a lot like my dad's cousin Martha Volz.  Could that be her?  Are Bob and Lucille her parents?  And who's the child in the front?  Questions.....