Hmm
Perhaps a StoryBoard showing all the branches and such.
Easy to see who is with whom.
Maybe use a Container to hold the whole Family.
Each Family is in a Container
(not tried yet but I think an Object can be in More than One)
Then Use Group or just make a new one Family
If I were doing it this all would go in the World Section, as it is back ground.
YMMV
Could use Relationships but I think that would be messy to setup,
the Story Board gives a a View layout
the Container a way to hold them all
I would bet there are at least 10 more ways though
Hope it helps a little