The handwritten letter touches on her improving health since the attack but says she struggles to understand what happened to her.
"I am making good progress towards recovery, but it is sometimes hard to understand what exactly happened to me on the 23/9," she wrote.
"I feel so fortunate that people have been so kind to us since then."
But she was looking forward to the day when she could return back to her husband and their six children.
"I can't wait till I am able to be at home. I miss being there with my family."
In a significant step towards her recovery the Herald on Sunday can reveal the 43-year-old is set to make a short visit home from the rehabilitation centre she is staying in.
Husband Peter Thomas told the Herald on Sunday the very first visit to gently ease back into life outside the clinic had been kept secret from her children.
"Lucy's planning to surprise all the children by turning up at home," said Thomas. "She's really excited about that."
The outing marked an important step in her recovery even if it was only to be a short visit, he said.
Thomas said his wife continued to make good progress and was keeping positive.
"We are amazed with her strength and determination, and thankful that she is getting better each day," he said.
She had just shifted into a house at the rehabilitation centre and this week managed a 30 minute walk with a physiotherapist.
Visits with closest family members - including her youngest pre-schoolers - had stretched to an hour at a time.
Thomas said he continued to be humbled and overwhelmed by the amazing public response.
Last week the Help Lucy givealittle page was closed with a record $269,934 donated towards Knight's recuperation.
Heart-rending stories open people's wallets, p12-13
