Who said "To persist through adversity is to prove one's mettle."?

This quote is attributed to Mary Wollstonecraft Shelley.

To persist through adversity is to prove one's mettle. - Mary Wollstonecraft Shelley

"To persist through adversity is to prove one's mettle."

Mary Wollstonecraft Shelley Perseverance

Novelist Poet English 1797–1851

"Nothing contributes so much to tranquilize the mind as a steady purpose."

"I am a writer, therefore I am not a respectable woman."

"The beginning is always today."

"No creature is fully employed whose passions are not engaged."

"Perseverance is the key to success."

"Don't give up on what you believe in."

"I've been through worse."

"You learn to live with the pain."