[Mary]'s brother [Dennis] and her went to get ice cream. [Dennis]'s sister [Natalia] asked him for some help planting her garden.
('Natalia', 'Mary')
[Dennis]'s sister [Natalia] asked him for some help planting her garden. [Mary]'s brother [Dennis] and her went to get ice cream.
[{('Natalia', 'sister', 'Mary'): [('Natalia', 'brother', 'Dennis'), ('Dennis', 'sister', 'Mary')]}]
['brother', 'sister']