The service will start at 2:30 p.m. at The Sequoias, 501 Portola Road in Portola Valley.
Ms. Johnson was born in San Jose, the oldest daughter of Albert and Eva Hackman. As a student at San Jose High School, she was active in the First United Methodist Church. It was there that she met her future husband, John R. Johnson, son of the newly arrived minister.
During World War II, the U.S. Navy sent Mr. Johnson to Asbury Park, New Jersey, for training and 20-year-old Ms. Hackman took the train across the country alone to marry her sweetheart. The Johnsons were married for 66 years.
After the war, Ms. Johnson earned a bachelor's degree in elementary education from San Jose State University. The couple settled in Menlo Park and she taught at Addison School in Palo Alto. Mr. Johnson served as city manager of Menlo Park and then as executive administrator of the Palo Alto Medical Foundation.
While raising her two children, Ms. Johnson was an energetic volunteer, committed to social justice, say family members. She served on the board of the Children's Health Council, the League of Women Voters, and other organizations.
"Mom never could say no when someone needed something done," her son Steven recalled. "She always had some project laid out on the dining room table, but every Friday she'd clear it off in time for whatever party she was having that weekend."
In 1969, when busing students from East Palo Alto to Menlo-Atherton High School provoked racial tensions, Ms. Johnson led efforts to reach out to parents in both communities, say family members.
A gifted photographer who loved hiking and traveling, Ms. Johnson went back to San Jose State at age 50 to earn a master's degree in instructional technology.
Ms. Johnson was a gracious hostess, who put people at ease, say family members. "Mom always looked put together and elegant, even in her last years," her daughter Kris recalled.
In 1998, the Johnsons moved to The Sequoias, where she led an art therapy program for the memory impaired.
Survivors include her husband, John Johnson; son Steven Johnson of Petaluma; daughter Kristina Johnson of Truckee; and two granddaughters.
Contributions may be made to the Children's Health Council, 650 Clark Way, Palo Alto, CA 94304; or the Palo Alto Medical Foundation, 795 El Camino Real, Palo Alto, CA 94301.