A Newcastle Supreme Court jury on Friday rejected Timothy Andrew Whiteley's claims he never touched the child.

Whiteley, 28, who had been in a relationship with the toddler's mother, told police he initially believed the girl had fallen out of bed and hit her head.

The toddler, weighing 11kg and standing 84cm tall, died from multiple injuries, including bleeding to the brain, broken ribs, a collapsed lung, lacerations to her liver and bleeding in her abdominal cavity.

The jury was told the toddler had suffered a number of blows or kicks to the body.

Her bloodstained, size-one pink Minnie Mouse pyjamas were later found in the bathroom.

The crown case against Whiteley, 28, who worked as a chicken chaser for Steggles, was he had been the only adult in the toddler's bedroom when she was attacked in a house in the Hunter region on June 19, 2018.

Whiteley claimed he didn't cause the girl's injuries or take part in the attack.

The toddler's mother - who has been charged with manslaughter - had also denied inflicting the injuries.

The mother will stand trial next year accused of gross criminal negligence for failing to provide the toddler with proper medical assistance or immediately call a doctor or an ambulance.

When defence barrister Peter Krisenthal accused the mother during the trial of attacking the toddler before the girl was put to bed at about 11.30am, she denied it.

One key piece of evidence at trial was the mother's claim that as Whiteley was performing CPR on the toddler before an ambulance was called, he said, "Don't you die on me, you little bitch".

Mr Krisenthal put it to the mother she was lying and had made up the comment to divert attention away from her and muddy the waters to Whiteley's detriment.

"I feel like you're wrong," the mother replied.

According to the crown case, Whiteley and the girl's mother were the only adults inside the house with the toddler when there was a loud thud heard by a visitor just before 12.20pm.

Prosecutor Lee Carr SC said the toddler was carried from the bedroom area soon after by Whiteley in a clearly distressed state, unconscious and not responding. But an ambulance was not called until 4.59pm.

The toddler was pronounced dead at 6.03pm at John Hunter Hospital.

Justice Stephen Rothman adjourned the case to February 25 for a sentence hearing.

Australian Associated Press