[Lillian] went shopping with her son [Timothy] and her brother [Nicholas].
('Nicholas', 'Timothy')
[Lillian] went shopping with her son [Timothy] and her brother [Nicholas].
[{('Nicholas', 'nephew', 'Timothy'): [('Nicholas', 'sister', 'Lillian'), ('Lillian', 'son', 'Timothy')]}]
['sister', 'son']