In 1934, Ware married actor Will Geer, with whom she had three children. She and Geer were politically-minded and relocated to Los Angeles in the early 1940s and settled in Santa Monica so that Geer could pursue his movie career. In 1951, the passionately left-wing Geer became blacklisted by Hollywood for taking the Fifth Amendment and refusing to testify before the House Un-American Activities Committee. With Geer's film career destroyed, and falling into financial difficulties, the couple lost their Los Angeles home. The pair divorced in 1954 but remained close friends. Ware later married actor David Marshall, with whom she had one child, a daughter, Actress Melora Marshall. They later divorced. Ware and Geer reunited in 1973 and subsequently co-founded the Will Geer Theatricum Botanicum, which was on five acres of land that Ware purchased in Topanga Canyon for $10,000. The burgeoning theater officially opened as a summer theater in 1973. She stayed by Geer's bedside as he died of a respiratory ailment in 1978. In 2000, Ware published her own memoir Fantastic Journey, My Life with Will Geer.

Ware made her Broadway debut in Let Freedom Ring (November 6, 1935–February 1936), co-starring husband Will Geer, whom she had married in 1934. The couple appeared together in other New York plays, including Bury the Dead (1936), Prelude (1936), 200 Were Chosen (1936) and Journeyman (1938), and Six O'Clock Theatre (1948), all of which were short-lived.

She made her on-screen debut in 1978, when she appeared in the television film, A Question of Guilt. Subsequently, she appeared in her first feature film 1980, The Black Marble. Her second feature film was Dr. Heckyl and Mr. Hype, which featured Oliver Reed. She starred in 2010 in 1984. She is perhaps most recognized for her performance in the classic film Ron Howard's Cocoon, and appeared in the sequel Cocoon: The Return. She appeared in Critters 2: The Main Course as "Nana". She had roles in several other well-known films such as, Species, Practical Magic, with Sandra Bullock and Nicole Kidman, and Cruel Intentions, with Sarah Michelle Gellar and Ryan Philippe. Her role in the 1992 television film Crazy in Love earned her a CableACE Award for Supporting Actress in a Movie or Miniseries.

Ware died in 2005, due to complications of Parkinson's disease, aged 88, in Topanga, California. Her ashes and those of her husband, Will Geer, were scattered at their outdoor theatre.