I found this quote in the February 22, 1896 issue of the Michigan Messenger (published in Adrian, Lenawee County, Michigan). I have no proof it is from THE Susan B. Anthony, but, really, is there another Susan B??
"Susan B. Anthony says it is all right for a woman to 'pop the question' to a man she loves, whether its leap year or not. Now that woman as become a bread winner, she is no longer in a position to wait for proposals."
According to the Wikipedia page on Susan B. Anthony, she was born February 15, 1820 and died March 13, 1906.
* Photo courtesy of the Wikipedia page and public relations portrait of Susan B. Anthony as used in the History of Woman Suffrage by Anthony and Elizabeth Cady Stanton, Volume I, published in 1881. Engraved by G.E. Perine & Co., NY