Justice Freddrenna M. Lyle said being an alderman for the South Side’s 6th Ward was the hardest job she ever had, with her legal background serving as a “double-edged sword” in helping her community.The 1st District Appellate Court justice, who was then an attorney, was appointed to the position in 1998 by Mayor Richard M. Daley. She had been recommended for the post by then-6th Ward alderman John O. Steele, who she had gotten to know through the Cook County Bar Association.“My first response was …