Justice Mary Peters convicted him on both charges and issued a three strikes warning under the Three Strikes legislation.
He was remanded in custody for sentencing in July.
Hurinui was a mother of six children at the time of her death.
Relatives, including her parents, were in the public gallery to hear Edwards admit his guilt.
'Relief at guilty pleas'
Outside court, a relative said they were pleased he admitted the charges although believed the Crown had a strong case against him.
"Yeah it saves it going to trial, and all the people that were involved in it ... but there were no buts about it, he was going to be found guilty for it."
The relative said Hurinui lived with her older brother and it was him, and his workmate, who ended up finding his bloodied and beaten sister in the house after arriving home from a work function.
He was particularly thankful that they wouldn't have to re-live what they saw that day.
He said Edwards also lived at the house but had only been there for about three weeks.
He said Hurinui's baby boy was now 3, but he was "learning at the level of a 4 and a half year old".
"He's my little Mr Danger, he is."
Hurinui's parents were now bringing up the toddler, he said.
Hurinui was one of five siblings, the second oldest but the only girl, he said, however she could hold her own in most situations.
"She's our only sister, out of four boys. She grew up the tough one out of all of us," he laughed.
"She was mean, she was hard, tough as. When I found out I couldn't believe it ... I didn't think anyone would kill my sister."
The family would be back to see Edwards get sentenced in July.
