Debra Tate, whose pregnant sister Sharon was slain in 1969 by the murderous followers of Charles Manson, has spent much of her life trying to divert attention from the cult leader and keep him in prison.

Her job got tougher with the news that Manson, now 80, plans to marry a 26-year-old woman who moved from the Midwest years ago to be near him.

Debra Tate calls the development "ludicrous" and "insane," but says she is not surprised.

"It's always something with him," she said.

Tate said Manson's bride-to-be, Afton Elaine Burton, known as "Star," seems to believe that Manson is leading a movement to save the environment.

Its name, ATWA — which stands for air, trees, water, animals — was emblazoned on a T-shirt worn by Burton when The Associated Press interviewed her on Monday.

"I wonder how long it will take for her to figure out this is just a con," Tate said. "It makes me wonder what is missing in her life that she would want to marry an 80-year-old man. Is she a victim? Is she mentally deranged?"

Burton has said she loves Manson and wants to help exonerate him. Marrying him would provide access to information denied to nonrelatives, she said without elaborating.

Tate, 62, recently published a coffee table book about her sister.

"There are no M words in the book. No Manson, no murder," Tate said Tuesday. "It's a celebration of Sharon's life, her fashion sense, her physical beauty and her spirit."

With an introduction by Sharon's widower, director Roman Polanski, the book is entitled "Sharon Tate Recollection."

Sharon Tate was 26 and more than 8 months pregnant when she was killed with four other people. The next night, grocers Leno and Rosemary La Bianca were stabbed to death across town.

Manson later stood trial with Susan Atkins, Patricia Krenwinkel and Leslie Van Houten. All were sentenced to death as was a fifth killer, Charles "Tex" Watson. When the death penalty was outlawed briefly in 1972, their sentences were commuted to life in prison.

A self-imposed purgatory followed for the family of Sharon Tate. Her mother and two sisters committed themselves to attending every parole hearing for every Manson family member to argue against their release.

Debra Tate is one of the few people still alive to carry on that cause. Foremost in her mind is preventing the spread of Manson's Internet following.

"I don't want any more heinous actions by another family like his because of something I didn't do," she said.