Mary Tyler Moore, who was unaware of Harper's illness until Harper called her the day before the story broke in People magazine, said in a statement, "I'm absolutely devastated by this news…Valerie has given so much joy, laughter and love to the world — I join her fans and send much love and positive thoughts to her and her family during this difficult time."

Betty White, who played "Happy Homemaker" Sue Ann Nivens on the award-winning comedy, told the New York Post, "Here I go wheezing on at 91 years old, and this beautiful, beautiful lady is facing something far too soon. We all love her so much, and we are going to make the most of every second we can."

Ed Asner, who was seen on Broadway earlier this season in Grace and who played news producer Lou Grant on "The Mary Tyler Moore Show," also spoke with the Post and said, "I have every confidence in the world that she will shock the hell out of us and survive — to keep functioning as the great talent and human that she is."

The 73-year-old Harper, who will forever be remembered as Mary Richards' best friend, window dresser Rhoda Morgenstern on "The Mary Tyler Moore Show" and its subsequent spin-off "Rhoda," has leptomeningeal carcinomatosis and may have "as little as three months left to live," according to People.

The celebrated artist, who plans to face her final days with "courage and humor," told People, "I don't think of dying… I think of being here now." *

Harper's memoir, "I, Rhoda," was released earlier this year by Gallery Books.

The hardcover tome traces Harper's career from Broadway chorus dancer to her breakout role as Rhoda Morgenstern on "The Mary Tyler Moore Show." That situation comedy, according to Harper, "reflected the way more and more real women were living in the 1970s. It was refreshing and invigorating and addressed the changing attitude towards women in the workplace that had been rippling across the country."

Harper spent nine years as Rhoda Morgenstern; although the first season of "The Mary Tyler Moore Show" was not a ratings success, Harper took home the Emmy Award for Best Supporting Actress. After that first season, the show was solidly in the top 10 for years, and Harper won two more Best Supporting Actress awards. From that success came the spin-off show, "Rhoda," and a Best Actress Emmy.

In her memoir, Harper, according to press notes, "candidly writes about the pressures of starring in her own sitcom — including how Rhoda's on-screen divorce rocked the television landscape and how in her subsequent series, 'Valerie,' she was wrongfully fired from her own show."

"I, Rhoda" also explores "the time after the show's cancellation. Valerie was involved in the feminist movement and worked on the passage of the Equal Rights Amendment (where her volunteer tutor was none-other than Gloria Allred). She also worked on The Hunger Project, an organization that had her visiting Kenya, Uganda, and Somalia."

The book also discusses Harper's recent Broadway outing, portraying Tallulah Bankhead in Looped. During preparation for the show's New York premiere, the actress was diagnosed with lung cancer, a revelation that she discusses for the first time in her memoir.