It added: "Any koha however small would be gratefully appreciated."
The family were waiting for Mrs Peniamina's body to be released for repatriation to New Zealand, to be laid to rest in Auckland, the post said.
Messages of support have flooded in on the post, which has been shared by around 60 people, many saying they had donated to the fund.
Mrs Peniamina had been due to return home to New Zealand to visit her cancer-stricken mother Anevili Potter. She was last in New Zealand just weeks ago to see her sick mother, and another visit was planned in two weeks. Yesterday, Mrs Peniamina's relatives gathered at the family home in Manurewa to mourn her death.
Mrs Potter was too upset to speak, but Mrs Peniamina's sister, Sylvia Potter, said the family were struggling to understand what had happened.
"We are still trying to process this, we still can't believe what has happened, it is just so hard to take in," she said. "We are grieving for Sandra and we are all in a state of shock."
Neighbours in the Brisbane suburb of Redcliffe called emergency services on Thursday night after hearing screams and finding the injured 29-year-old in her driveway.
Paramedics described the scene as one of the worst they'd seen.
Mrs Peniamina's four children were asleep in the house.
Yesterday, a close relative said she last heard from Mrs Peniamina on Thursday morning. "She said she was happy," the relative, who lives in Otara but declined to be named, said.
"I didn't hear anything from her on Thursday night or Friday morning which was unusual but I assumed she didn't have any internet. When I heard what happened I was stunned. I just couldn't believe it.
"Sandra and I were very close," she said. "We grew up together and she was a real people person. She was outgoing and made lots of friends."
The relative said the Peniaminas had moved to Australia about five years ago.
"I really feel for the kids. Four young children have been left without a mother."
Friend Petala Eteuati said Mrs Peniamina had a huge group of friends from James Cook High School, which they attended together.
"It was just her personality. She loved to joke, she had a weird sense of humour and she was the type of friend that was always there for you.
"She spoke about her kids all the time. They meant everything to her."
Mr Peniamina, 35, also from Auckland has been treated at Redcliffe Hospital for hand injuries.
He was charged with murder at a bedside hearing on Friday before undergoing surgery.
To donate
The Koha Shed Australia Inc
Commonwealth Bank Aust. B.S.B: 064 087, Acct: 1014 5297, REF: PeniaminaTrust
