[Amy]'s father [Clarence] took care of her son [Glen] for the weekend.
('Glen', 'Clarence')
[Amy]'s father [Clarence] took care of her son [Glen] for the weekend.
[{('Glen', 'grandfather', 'Clarence'): [('Glen', 'mother', 'Amy'), ('Amy', 'father', 'Clarence')]}]
['mother', 'father']