What Lizzy heard was senior police officer Amy Scott shooting Joel Cauchi, 40, who fatally stabbed six people and injured at least 12 more at the busy shopping centre on Saturday, April 13. Yixuan Cheng, Pikria Darchia, Jade Young, Dawn Singleton, Ashlee Good and security guard Faraz Tahir all died in the attack that NSW Police Commissioner Karen Webb said targeted women.

52-year-old Lizzy lives and works in Mudgee and was in Sydney to pick up and bring her 13-year-old daughter home for the holidays. She described the initial moments of panic and confusion as people were trying to piece together the reality of the situation as it was happening.

"...It was very loud and everyone immediately dropped what they were doing. Someone was screaming and someone said there was a gunman," Lizzy said.

She and several other shoppers took refuge at the back of the store in the change rooms.

"They were all full. Then this lady opened the door, looked out and said 'come in, come in'," she said.

"Everyone was just quiet because we were thinking that there was a gunman on the loose and we hid behind so that our feet couldn't be seen. There was no lock on the door, so we were all holding our breath, holding hands, terrified. I called my husband, I said: 'there's been shots fired and we're cowering in the change rooms. Can you find anything out?'"

Lizzy said she's thankful her daughter didn't come shopping with her. "She would have gone off for bubble tea and would have been right in the path of the guy," she said.

The frightened group heard alarms sound in the centre and soon after police came and escorted them from the premises.

"We ended up right at the front. And so we were watching as bodies were just coming out. People covered in blood had been trying to help. People were sobbing and hysterical," Lizzy said.

During the chaos, Lizzy's phone died and it was only when a friendly shop owner let her into the closed store that she was able to get some charge and let her family know she was okay.

"My husband was not knowing whether I was alive or dead, as did everyone who read my Facebook post - they were a bit concerned," she said.

"By this stage, it'd become clear that there were mass casualties and that a lot of people had witnessed what had happened. I was very glad that I didn't see the actual violence towards it. Because the thoughts of somebody harming a baby is just... just beggars belief, harming innocent women, harming the innocent security guards. Somewhere that is such a safe place that everyone knows..."

Not wanting to wait outside the shopping centre which was swarming with police and confused shoppers and bystanders, Lizzy found an area away from the chaos and was picked by some friends who came to her aid and stayed with them for the night before heading back to Mudgee on Monday.

"I couldn't sleep and I couldn't eat - just so much adrenaline in my system - I was shaking badly. Monday night my husband decided to drive down and pick me up - I just wanted to be home in the country.

"[I] just felt very unsafe in the city with all the sirens and commotion. It was really eerily quiet in that whole of that area was just in shock. I think everyone knows that area so well. Everyone was affected."

Speaking out about what happened, Lizzy said her support network has been amazing.

"People have just been so kind to reach out. People, as soon as they heard have said: 'I'm here if you need to talk.'"

More than $555,000 has been raised for the family of 38-year-old mother Ashlee Good, whose nine-month-old baby Harriet was in a serious but stable condition after the attack.

"Ash was a ray of sunshine and positivity [sic] in every aspect of her life and died a hero saving her little girl from the most unspeakable evil," GoFundMe organiser Steven Foxwell said.

"We are united in our devastation that her bright future was cut short in this way. Her beautiful and warm spirit, drive and energy inspired us all."