Farrah Fawcett's best friend Alana Stewart is opening up to ET's Mary Hart about Farrah's battle with cancer and her current health.

Alana tells Mary that Farrah, who has always been known for her trademark beautiful locks, began losing her hair around February of this year, during their last trip to Germany.

"I think it was surprising because she'd gone through almost two years of treatment without losing it," she says. "Then when she did start to lose it, it was very surprising in the beginning and then shocking. Then she kind of joked about it. I mean she took it like she did everything else. She took it in her stride."

Alana also tells Mary about Farrah's response to seeing her son Redmond O'Neal and reveals that Farrah is not aware that her son is in jail.

"She was so happy to see him I think it just gave her new inner strength," Alana says. "She's using all her strength to battle cancer. There's no reason that she should know that her son is in jail. She thinks he's in rehab."

Alana tells ET about Farrah's request to her doctors.

"She has talked about dying," Alana says. "She's said many times 'all I want to know is if I have two months left to live that the doctors tell me because I need to know. There's a lot of things I need to do.' So far no one's told her that."

Although Farrah has tried to stay positive through her cancer battle, Alana reveals that there have been some emotional times.

"She hasn't cried a lot," she says. "There's times during these last two years where she has broken down and cried, and then she'll say, 'I'm sorry, I'm sorry I don't mean to be a baby.' And I've said, 'baby, are you kidding? I couldn't go through one tenth of what you've gone through.' And I've said to her, 'you're the most amazing, the strongest person I've ever known,' And she is."

Catch the rest of Mary Hart's interview with Alana Stewart this Thursday on Entertainment Tonight.