Lockhart died of natural causes at home in Santa Monica, California, with her daughter, June Elizabeth, and granddaughter, Christianna, by her side, her spokesperson said Saturday in a statement.

June Lockhart, who became the archetypal TV mom of the 1950s and 1960s with her roles on the campy sci-fi series “Lost in Space” and alongside a collie and a little boy on the family drama “Lassie,” d...