A family representative says Betty Sue Lynn, daughter of country singer Loretta Lynn, has died.   She was 64.   According to the statement from the family, Lynn died Monday from complications of emphysema in Waverly, Tenn., near her mother’s ranch in Hurricane Mills.   Betty Sue was the oldest of Loretta Lynn’s  six children with husband Oliver “Doo”.   Betty Sue Lynn  is survived by two daughters, Lynn Markworth and Audrey Dryer, and five grandchildren.   Loretta’s website has this statement “The Lynn Family appreciates all your prayers, love and support of our family’s loss. “