Margaret White Jones, a longtime Belvedere resident whose decades of community leadership included stints on the Reed Union School District and Belvedere-Tiburon Library Agency boards, died May 21 of complications from Alzheimer’s disease. She was 90. In addition to serving eight years each as an elected member of the Reed district board and as an appointed member of the Library Agency board, Mrs. Jones led the League of Women Voters of Marin. In all of those roles, she championed the issues of