"He was there shovelling dirt into the grave, carrying the coffin," a cousin said.
Reo Te Whetu Marama Marsh, 34, was initially charged with grievous bodily harm and strangulation but this was upgraded to murder on Tuesday after Benedito's death.
Marsh also allegedly took their 11-month-old son, prompting authorities to issue an amber alert, the Courier Mail reported.
The baby was returned to a police station by two women early on Sunday morning, and
Marsh was arrested in the Brisbane suburb of Oxley later the same day.
He is expected to appear next in Southport Court in January.
Benedito was surrounded by family members and close friends when hospital staff turned off her life support on Monday.
Teu told the Courier Mail Benedito was a selfless person who was always happy and laughing. "It was never really about her, it was always about you."
"She was really very selfless, whatever she was going through she would just sweep it under the rug and focus on keeping you happy.
"She was the goofiest person I have ever met in my life. She was so bubbly. She had an infectious personality and even if you were sad she would do whatever she could to bring you back up again, to make you laugh, to make you giggle."
They gave her the nickname Mama, because she was a great mum.
"She loved her child unconditionally," Teu told the Courier Mail. "Nothing was ever too hard … and she was always laughing with her baby. But she was amazing, as a first-time mother she never needed help – she knew what to do straight away and was always having fun and laughing with him."
The Herald understands Benedito's family are originally from the Cook Islands.
Many have paid tribute to Mama on social media, including high school friend Tiana Govan, who recalled having "a lot of fun memories" with her.
"You had an amazing heart and [you were] an amazing mum," she wrote.
Yani Palmer wrote: "Watch over us sister, guide us sister, and know that we got your back for baby and we will make you proud."
A family member wrote on Facebook: "I miss you so much, and I love you more than words can describe."
"May you now rest peacefully with nana and in God's loving arms."
Two crowdfunding pages have been started for Benedito's 11-month-old son.
"We will miss her so much, and now have a duty to raise her son who is surrounded by so much love!" said the Givealittle page.
If you're in danger now:
• Phone the police on 111 or ask neighbours of friends to ring for you.
• Run outside and head for where there are other people.
• Scream for help so that your neighbours can hear you.
• Take the children with you.
• Don't stop to get anything else.
• If you are being abused, remember it's not your fault. Violence is never okay
Where to go for help or more information:
• Women's Refuge: Free national crisis line operates 24/7 - 0800 refuge or 0800 733 843 www.womensrefuge.org.nz
• Shine, free national helpline 9am- 11pm every day - 0508 744 633 www.2shine.org.nz
• It's Not Ok: Information line 0800 456 450 www.areyouok.org.nz
• Shakti: Providing specialist cultural services for African, Asian and middle eastern women and their children. Crisis line 24/7 0800 742 584
• Ministry of Justice: www.justice.govt.nz/family-justice/domestic-violence
• National Network of Stopping Violence: www.nnsvs.org.nz
• White Ribbon: Aiming to eliminate men's violence towards women, focusing this year on sexual violence and the issue of consent: www.whiteribbon.org.nz
- Editor's note: An earlier version of this story carried information from the Australian newspaper The Courier-Mail that referred to Benedito's mother dying, this has now been corrected
