[John]'s grandfather, [Clarence], picked him up from school. [John] and his sister [April] stood in line at the fair.
('April', 'Clarence')
[John] and his sister [April] stood in line at the fair. [John]'s grandfather, [Clarence], picked him up from school.
[{('April', 'grandfather', 'Clarence'): [('April', 'brother', 'John'), ('John', 'grandfather', 'Clarence')]}]
['brother', 'grandfather']