WASHINGTON — The junior lieutenant in charge of navigating the USS Fitzgerald when it collided with a commercial vessel pleaded guilty Tuesday to dereliction of duty and acknowledged her role in the deaths of seven sailors last year. Lt. j.g. Sarah Coppock cried during her court-martial at the Washington Navy Yard. She was sentenced to forfeit half of her pay for three months – an additional month on top of the two she forfeited as her nonjudicial punishment. She also received a letter of reprimand. “Not a day goes by where I haven’t thought about what I could have done...