[Clarence] took his son [Dale] to baseball practice. [Clarence]'s daughter [Nancy] was busy at soccer practice.
('Dale', 'Nancy')
[Clarence] took his son [Dale] to baseball practice. [Clarence]'s daughter [Nancy] was busy at soccer practice.
[{('Dale', 'sister', 'Nancy'): [('Dale', 'father', 'Clarence'), ('Clarence', 'daughter', 'Nancy')]}]
['father', 'daughter']