[Amy] is very proud of her son. His name is [Glen]. [Mary] was playing in the sandbox with her brother [Glen].
('Mary', 'Amy')
[Mary] was playing in the sandbox with her brother [Glen]. [Amy] is very proud of her son. His name is [Glen].
[{('Mary', 'mother', 'Amy'): [('Mary', 'brother', 'Glen'), ('Glen', 'mother', 'Amy')]}]
['brother', 'mother']