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?
Yes, sometimes questions are bit GK as well.
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.