There's a lot on her on the web. I searched by "Julia Cooper," and found one of the most detailed answers right here on answers.com. http://www.answers.com/topic/anna-julia-haywood-cooper One of the...
I was looking up this myself. It appears she wrote a poem late in her life. see: http://findarticles.com/p/articles/mi_qa3626/is_200610/ai_n18705756/pg_8
Stand up to big people. Get beaten up and stand back up. Beat up someone bigger than you. Attempt something really hard and other such acts of courage or, to use a simpler word "bravery".