Answer:
her father's wish that she were a boy
Step-by-step explanation:
The death of the only son in Judge Daniel Cady's family struck a deep blow in his heart. Their only son had just returned from Union College only to die at home when Elizabeth was just 11 years-old.
Now left with five girls, Judge Daniel Cady was thrown into so much anguish, that when Elizabeth came to comfort him, he wished that she were a boy. This lamentation by her father was the driving force that made Elizabeth determined to prove that both genders were just as important. She promised her father that she would try to be all that her brother was.