[Jacob] was delayed picking up his sister, [Heidi], from class. Thankfully, [Nancy]'s mom, [Heidi], was already there.
('Jacob', 'Nancy')
[Jacob] was delayed picking up his sister, [Heidi], from class. Thankfully, [Nancy]'s mom, [Heidi], was already there.
[{('Jacob', 'mother', 'Nancy'): [('Jacob', 'sister', 'Heidi'), ('Heidi', 'mother', 'Nancy')]}]
['sister', 'mother']