[Lena]'s daughter, [Pamela], just graduated high school. [Lena] bought her son [Chris] a car. [Chris]'s sister [Martha] was jealous.
('Martha', 'Pamela')
[Lena] bought her son [Chris] a car. [Chris]'s sister [Martha] was jealous. [Lena]'s daughter, [Pamela], just graduated high school.
[{('Martha', 'sister', 'Pamela'): [('Martha', 'mother', 'Lena'), ('Lena', 'daughter', 'Pamela')]}, {('Martha', 'mother', 'Lena'): [('Martha', 'brother', 'Chris'), ('Chris', 'mother', 'Lena')]}]
['brother', 'mother', 'daughter']