Examples of Metaphors:
"Esperanza stood on one side and Miguel stood on the other side and the river could never be crossed"
"She snapped the edge of the shell and pried it apart"
It means that when marta teased her she fell apart, she was sad because marta had calle dher cinderella, when she did not know how to sweep with the broom.
I think that marta was mean to esperanza and thats why the metaphor was "She snapped the edge of the shell and pried it apart".