By Lawrence Hurley WASHINGTON (Reuters) – If confirmed as its first Black woman justice, Ketanji Brown Jackson would add not only racial and gender diversity to the U.S. Supreme Court but would also bring a varied legal background including a stint representing low-income criminal defendants. Jackson, 51, served early in her career as a Supreme Court clerk for Justice Stephen Breyer, whose retirement announced in January created a vacancy on the nation’s top judicial body that President Joe Biden picked her to fill. Biden, a Democrat, last year appointed Jackson to an influential Washington-ba…