[Lena] and her brother [Joshua] played with his daughter [Andrea] on the playground while [Andrea]'s grandmother [Frances] was in physical therapy.
('Lena', 'Frances')
[Lena] and her brother [Joshua] played with his daughter [Andrea] on the playground while [Andrea]'s grandmother [Frances] was in physical therapy.
[{('Lena', 'mother', 'Frances'): [('Lena', 'brother', 'Joshua'), ('Joshua', 'mother', 'Frances')]}, {('Joshua', 'mother', 'Frances'): [('Joshua', 'daughter', 'Andrea'), ('Andrea', 'grandmother', 'Frances')]}]
['brother', 'daughter', 'grandmother']