The two young women, who were lovers, hatched the plan to attack Ms Brook as part of a Satanic plot.
They were sentenced to 11 and 20 years in prison respectively for attempted murder.
Now, Bird has applied for parole, and could soon be freed, news.com.au reported.
Ms Brook, who is now 72 and lives in Christchurch, said she was aware of the move but was "happy" for Bird.
"It comes as no surprise that she has applied for it (parole). I have no problem with it. She has done the time. I am happy for her so long as she goes home to her parents.
"I am not bitter. I would not be where I am today if I carried my bitterness, which I had originally, around with me."
Ms Brook had her throat cut almost from ear to ear in the attack.
The pensioner spent nine days in hospital fighting for her life and suffered damage to her vocal chords.
Schipper was released from prison in 2005 after serving fewer than six years.
Ms Brook said she had forgiven her attackers and hoped to get on with her life.
"I might forgive but I never forget. It happened 13 years ago but it is with me every day. The other girl (Schipper) was released many years ago and that was fair enough. I have to get on with my own life.
"I have been well-supported by a lot of friends. They have helped me a lot. A lot of people don't think I should forgive them, very few people, but that is how I feel.
"I want it all to be finished so I can get on with the final stage of my life."
