"We are heartbroken to announce the passing of our dear mother, Florence Henderson, from heart failure," the Henderson family said in a statement. "On this day of thanks, our beloved mother was surrounded by her devoted children and dearest friends. We thank all of her fans for their many years of love and ask that we be allowed to grieve in private."
Pressman said, "Florence was the most vibrant and caring woman I have ever known. She never had an unkind word about anyone. She was a wonderful mother and was so proud of her four children and five grandchildren."
Henderson is survived by "her adored children — Barbara, Joseph, Robert, Lizzie — and their respective spouses, as well as her five grandchildren," said the family statement.
Henderson had her children with her first husband, Ira Bernstein, to whom she was married from 1955 to 1985. She married hypnotherapist John Kappas in 1987. He died in 2002.
Maureen McCormick, who played Henderson's onscreen daughter Marcia Brady, tweeted, "Florence Henderson was a dear friend for so very many years & in my [heart] forever. Love & hugs to her family. I'll miss u dearly #RIPFlorence."
McCormick followed up with a photo of the two of them, writing, "You are in my heart forever Florence."
"The Brady Bunch" aired from 1969 to 1974 on ABC, and it returned in the form of various specials, including "The Brady Bunch Hour" in 1977, "The Brady Brides" in 1981 and "The Bradys" in 1990.
Born in Dale, Indiana, Henderson kicked off her show business career with roles on Broadway, and she soon starred in the national tour of Rodgers and Hammerstein's "Oklahoma!"
Among her earliest TV credits is an appearance on "The Tonight Show" as its first female guest host.
But it wasn't until 1969, when she landed the role of Carol Brady, that she became a household name.
ABC News' Matthew Fuhrman contributed to this report.