The former model and fourth wife of the hugely successful late singer died on Tuesday at her home in California.
Barbara married Frank in 1976 and remained his wife for almost 22 years - the longest of his 4 marriages.More news: Doctors treating Charlie Gard get death threats
Barbara Sinatra, the longtime wife of legendary crooner Frank Sinatra, known as "Lady Blue Eyes", has died at the age of 90.
From left, Frank Sinatra, unknown, Flip Wilson, Barbara Sinatra, Tina Sinatra and Frank Sinatra Jr. are seen July 27, 1980 at the Sahara in Las Vegas.
Funeral arrangements will be announced in a few days, according to John E. Thoresen, director of the Barbara Sinatra Children's Center Foundation.More news: Detwiler Fire Now 30 Percent Contained
Frank remained friendly with all of his previous wives, something that Barbara said never bothered her. They remained Wednesday until his death in 1998 at age 82.
She was the last of Sinatra's four wives, their partnership being the longest lasting of the Fly Me To The Moon singer's marriages.
"Barbara started raising funds for [the center] in 1985 with Frank's support", Thoresen told The Desert Sun. Her first marriage collapsed when she was caught having an affair with Zeppo Marx, an actor and comedian. "You worry about new ones, '" Sinatra said.More news: Ben Affleck Denies Rumors He Is Exiting 'Batman'
The family requests that memorial gifts be directed to the Barbara Sinatra Center for Abused Children, 39000 Bob Hope Drive, Rancho Mirage, CA, 92270. The center counsels physically, sexually and emotionally abused children.