In an interview on NBC's "Today" show, the ex-model spoke out for the first time since Farrah's funeral last month and described the final words she uttered to the "Charlie's Angles" star as the ailing icon lay on her death bed.
"I told her how much I loved her and that she was like a sister to me," Stewart said, "and she looked up at me and said, 'More than a sister.'"
Stewart appeared on the show to pedal her new book "My Journey With Farrah," which highlights grim moments in the star's 2 1/2-year battle with anal cancer like the time Fawcett vomited 75 times in 12 hours.
"Do you talk to a person about dying?" she writes in the book. "Do you tell them not to be afraid? Or do you just pretend everything is fine? I don't know .I wish someone would tell me. I don't know what my life will be like without Farrah in it."
Stewart, who had known Fawcett more than three decades, helped film the video diary-turned-documentary that chronicled the star's brave journey through gut-wrenching cancer treatments that proved unsuccessful.
"I never had more respect and admiration for anyone," she said. "I wanted the book to be an extension of the documentary."
Stewart made the media rounds to promote the popular TV documentary "Farrah's Story," which led many to question her motives for filming in the first place. Most recently Griffin O'Neal -- the estranged son of Ryan, who fathered Farrah's only son -- said he didn't trust the longtime pal.
"She was selling Farrah's stuff on eBay the day Farrah died," O'Neal told CNN. "I thought they were exploiting her. I think that they will continue to exploit her through the 'Farrah Story II' and Alana's new book."
Fawcett died on June 25.