Connally, the widow of former Gov. John Connally, died late Friday at Westminster Manor in Austin, said Julian Read, who served as the governor's press secretary in the 1960s.
"Total surprise," he said. "She has been extremely active and vital the past few days and weeks. ... It's a shock to all of us."
Connally had said the most enduring image she had of the Nov. 22, 1963, assassination was of a mixture of blood and roses.
"It's the image of yellow roses and red roses and blood all over the car ... all over us," she said in a 2003 interview with The Associated Press. "I'll never forget it. ... It was so quick and so short, so potent."
As the limousine carrying the Connallys and the Kennedys wound its way through the friendly crowd in downtown Dallas, Nellie Connally turned to President Kennedy, who was in a seat behind her, and said, "Mr. President, you can't say Dallas doesn't love you."
Almost immediately, she heard the first of what she later concluded were three gunshots in quick succession. Connally slumped after the second shot, and, "I never looked back again. I was just trying to take care of him," she said.