Never would she ever go home again. Never. Impossible father and an ignorant mother. Everyone thought she was exaggerating things. But she wasn't. No one, none who never lived there will ever understand the situation. 12 years were more than enough of frustration. Love is sometimes not enough to keep you grounded. It's a truth only people like Toph would understand. Thus, rather than the troublesome life, she proffered the lonesome journey.
No one can say she didn't try. She tried her best. But what did they do? They were afraid of even trying. Their framed minds put her through so much pressure and pain that at the end she was able to leave her misery for good.