Some thing else that is true about extended family sessions is that they are hard!  It is hard to schedule multiple house holds to be able to meet with the photographer during perfect lighting conditions.  It is also hard for the photographer to work with a large group, that typically includes children, and have everyone cooperate at the same time.  But the life long images make all of these challenges worth it.  For example, it is so special to have images of grandparents together with all of their grandchildren.