"She's flying now, free of her body," Henry's daughter, Erin Ellwood, wrote on Instagram. "She left on a countdown 4 3 2 1 @ 3:40pm. She was such an incredible woman in so many ways. This last year with her has been beautiful and heartbreaking."
Henry (birth name Gloria Eileen McEniry) was born on April 2, 1923 in New Orleans. She transitioned from Louisiana to La La Land by 1947-- the year she appeared in the films Sport of Kings, Keeper of the Bees and Bulldog Drummond Strikes Back.
Two of her biggest big-screen breaks (The Strawberry Roan (1948) and Riders in the Sky (1949)) co-starred singing cowboy and future Country Music Hall of Famer Gene Autry.
Henry regularly appeared in films well into the '50s, with additional roles of note coming in Lucille Ball's Miss Grant Takes Richmond (1949) and Marlene Dietrich's Rancho Notorious (1952) plus the sports films Triple Threat (1948) and Kill the Umpire (1950).
Television roles as either a heartthrob or wholesome mother came on '50s series The Abbott and Costello Show, My Little Margie, The Files of Jeffrey Jones, Perry Mason, The Life of Riley and Father Knows Best.
A run as Alice Mitchell, the mother of mischievous Dennis Mitchell and a creation of Hank Ketcham, still defines Henry's career and set the bar high for all TV moms to follow. The CBS sitcom co-starred Jay North and Herbert Anderson.
"Many of the fans say, 'Oh, I always wished you were my mom' and 'My mom was jealous of you, because I wanted you for a mom,'" she said in a 2011 interview (as quoted by The Hollywood Reporter). "Which is pretty funny, because I don't think my own children felt that way."
Henry went on to appear in a wide range of TV shows, including The Brady Brides, Dallas, Newhart, Silver Spoons, Simon & Simon, Mr. Belvedere, Doogie Howser, M.D. and Parks and Recreation.
She took a 30-year hiatus from movies after 1958's Gang War. She returned for two films directed by Walter Matthau's son, Charles Matthau: Doin' Time on Planet Earth (1988) and Her Minor Thing (2005).
Henry was married to Robert D. Lamb between 1943 and 1948. She wed architect Craig Ellwood in 1949; they divorced in 1977. The couple had three children: Jeffrey, Adam, and Erin Ellwood.