What would be an appropraite data structure to represent family hierarchy where each node is an individual and there in no requirement to keep "married to" relationship?
It is definitely n-ary tree.
Linked List can't represent someone having two children.
Binary tree can't represent someone having three children.
A graph can represent A's child to be the father of B if A and B are siblings. (Visualize it)
An n-ary tree would represent someone having n number of children, without disrupting the hierarchy.