She’s one of Carly’s sisters.
“He proposed to Joanna several years ago,” one insider tells us of Cronkite. “They were going to get married on the Martha’s Vineyard estate of her sister Carly Simon. But Walter thought he should ask for his children’s permission. They went bananas. Their mother, Betsy, was married to Walter for 65 years. And as far as they were concerned, there was never going to be another Mrs. Cronkite.”