[David] cooked her son [Brandon] his favorite meal yesterday because it was his birthday. [Lena]'s mother [Frances] took her to school Monday. [Lena]'s sister [David] took the bus to school.
('Brandon', 'Frances')
[David] cooked her son [Brandon] his favorite meal yesterday because it was his birthday. [Lena]'s mother [Frances] took her to school Monday. [Lena]'s sister [David] took the bus to school.
[{('Brandon', 'grandmother', 'Frances'): [('Brandon', 'mother', 'David'), ('David', 'mother', 'Frances')]}, {('David', 'mother', 'Frances'): [('David', 'sister', 'Lena'), ('Lena', 'mother', 'Frances')]}]
['mother', 'sister', 'mother']