[Nicholas]'s son, [Glen] and sister [Theresa] went biking by the coast today.
('Glen', 'Theresa')
[Nicholas]'s son, [Glen] and sister [Theresa] went biking by the coast today.
[{('Glen', 'aunt', 'Theresa'): [('Glen', 'father', 'Nicholas'), ('Nicholas', 'sister', 'Theresa')]}]
['father', 'sister']