[Nicholas]'s sister [Lillian] wanted [Nicholas]'s daughter, [Mary], to go with them to the theatre.
('Lillian', 'Mary')
[Nicholas]'s sister [Lillian] wanted [Nicholas]'s daughter, [Mary], to go with them to the theatre.
[{('Lillian', 'niece', 'Mary'): [('Lillian', 'brother', 'Nicholas'), ('Nicholas', 'daughter', 'Mary')]}]
['brother', 'daughter']