Dharminder Singh, 48, faced Toowoomba Magistrates Court on Monday by video link, two days after the search for Jana Armstrong ended in tragedy.
The 30-year-old mum had been missing for four days when her body was found by hunters in remote terrain near Toowoomba, west of Brisbane.
Singh's defence lawyer Ramli Salehkon said his client would fight the murder charge.
"He's OK. He's quite distressed," he told AAP in a statement.
"My client asserts his innocence. This matter will be defended - my client has rights.
"My client has co-operated with the police in the course of their investigations into this matter."
A large group of family and friends attended court on Monday including Ms Armstrong's four-month-old son, held by her sister Faith Isaacs.
Ms Isaacs thanked the community for its support after Singh's brief hearing, saying the child was doing as well as could be expected.
"I'm just glad he's in our arms," she told reporters outside court.
Ms Isaacs said it was always her sister's dream to be a mother.
"She loved every day, every minute, spending time with her son," she said.
"She was never away from him and she's just the most caring and loving person."
Ms Isaacs stepped up as the boy's carer a month after losing her own newborn baby, relatives said.
Ms Armstrong and her siblings had also lost their mum to breast cancer seven years ago while their father died of a heart attack five years ago, cousins Hannah and Lara Sweedman said.
"Jana was the glue for the family," they wrote on a GoFundMe fundraiser.
The campaign had raised more than $54,000 by Monday afternoon with the funds to go toward funeral costs and raising Ms Armstrong's child.
"Our family is absolutely devastated and trying to process this unimaginable loss," they wrote.
"We will make sure Jana's baby boy always knows just how deeply his mummy loved him and how incredibly special she was - her memory will live on through him forever."
Ms Isaacs confirmed in an online tribute she would take care of her beloved sibling's child.
"Losing my beautiful sister in this way is something I will never be able to understand or put into words," she posted on social media on Sunday.
"I promise you, Jana, your beautiful baby boy will always know exactly who his mummy was."
Singh was arrested hours after Ms Armstrong's remains were found late on Saturday.
Police are investigating the possibility the accused killer had moved Ms Armstrong's body in the period after she disappeared.
"This is a horrific crime," Detective Acting Inspector Brian Collins previously told reporters.
No relevant domestic violence protection order was in place in the relationship, he said.
Previously released footage of Ms Armstrong from the day of her disappearance showed her carrying her son and pushing him in a pram across a car park.
Police have been trying to trace the movements of Ms Armstrong and her white Hyundai Kona in the hours after she was last seen.
They are interested in any footage from between Toowoomba and Esk, along Esk Hampton Road and the New England Highway, between 10.30pm on July 7 and 1.30am on July 8.
Singh was remanded in custody and his matter adjourned until October 1.
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