A sad heart…It trembled for Mr. Rochester and his doom; it bemoaned him with bitter pity; it demanded him with ceaseless longing; and, impotent as a bird with both wings broken, it still quivered its shattered pinions in vain attempts to seek him.

– Charlotte Bronte

Jane Eyre, Chapter 28. After Jane has fled from Rochester her heart longs for the man she still loves. But because of her moral compass, with Rochester being a legally married man, she cannot act on it. She uses an animal simile to compare her sad heart to a bird with broken wings.