[Glen] brought his mother [Amy] as a guest to the Christmas party. [Jennifer], [Glen]'s sister, came as a guest of his friend.
('Jennifer', 'Amy')
[Glen] brought his mother [Amy] as a guest to the Christmas party. [Jennifer], [Glen]'s sister, came as a guest of his friend.
[{('Jennifer', 'mother', 'Amy'): [('Jennifer', 'brother', 'Glen'), ('Glen', 'mother', 'Amy')]}]
['brother', 'mother']