[Chris] took his sister [Pamela] out to dinner for her birthday. [Pamela] and her mother [Lena] went dress shopping on Saturday. [Charles] bought a new refrigerator for his mother [Lena].
('Charles', 'Chris')
[Charles] bought a new refrigerator for his mother [Lena]. [Pamela] and her mother [Lena] went dress shopping on Saturday. [Chris] took his sister [Pamela] out to dinner for her birthday.
[{('Charles', 'brother', 'Chris'): [('Charles', 'mother', 'Lena'), ('Lena', 'son', 'Chris')]}, {('Lena', 'son', 'Chris'): [('Lena', 'daughter', 'Pamela'), ('Pamela', 'brother', 'Chris')]}]
['mother', 'daughter', 'brother']