The mother of a three-year-old Sydney girl, crushed and killed by a sandstone Anzac monument, said online trolls have spread misinformation and exacerbated her trauma.

Indy Lee Henderson was crushed by the Anzac monument at the Black Head Bowling Club on the Mid North Coast of New South Wales in November 2016.

At the conclusion of the inquest into her death her mother Tamica Harrower read out a statement.

Indy Lee Henderson would be turning six in February. ( Supplied: Tamica Harrower )

"Indy was a beautiful girl with an infectious personality, loved by everyone she came into contact with. Indy is deeply missed by her family and friends," Ms Harrower said.

"Indy was the love of my life and not a day will go by that she doesn't remain in my heart.

"The inquest into the devastating death of our beautiful Indy and reliving the tragic events of that evening has been heartbreaking."

Inquest told structure unsafe

An engineer told the inquest that the sandstone structure was not properly secured to its base, enabling it to topple over.

The monument was built and erected in 1997 by stonemason John Edstein.

In a statement to police that was tendered in the NSW Coroner's Court, the now retired Mr Edstein, 80, rejected that the monument was not structurally sound.

The headstone on the Anzac monument weighed 425 kilograms. ( Supplied: Google Streetview )

"In my view it was a construction that met standards," Mr Edstein said.

Greater Taree City Council, now dissolved to join the Mid-Coast Council, had approved the monument development, but prior to giving it the go ahead the council deleted a condition in relation to the building application process.

That meant there were no conditions attached to the Anzac monument proposal.

Mum hits out at online trolls

Ms Harrower said comments by online trolls had added to her grief by blaming her for not properly supervising her daughter.

Ms Harrower told the ABC it was a tragic accident that could have happened to any family.

"Nasty comments of [untrue] information have sometimes turned my grief to anger. My poor Indy deserves better," she said.

"In Indy's honour we would like it duly noted that Indy was not on the memorial but simply walking past it at the time that it collapsed.

"Members of the public were at the club with their children on the evening of the tragic event — which we had no control over."

The inquest heard Ms Harrower was only five strides away from the monument when it toppled over.

Mystery surrounds boy who rode monument before collapse

The inquest heard children had been running around the Anzac monument and playing on it before it collapsed.

There was also evidence that moments before its collapse a boy was seen straddling it and riding it like a rocking horse.

Indy's family said they do not know who that boy was.

"The young child who was riding the monument has not been identified and his parents have not come forward," Ms Harrower said.

"We would like to categorically state that we have no ill feeling towards his family and we hope they are receiving some sort of counselling to deal with their grief around this event.

"It is important that we all remain positive and focussed on the issue.

"Our priority is to get answers as to why a horrific event could have occurred — taking such a young beautiful life — and to ensure that this never happens to another family."

Council audits public monuments and erects plaque in girl's honour

A planner from the Mid-Coast Council, Paul De Szell, said in the wake of Indy's death his staff had started checking the stability of monuments in the council's cemeteries and on other public land.

He said there are more than 26,000 monuments that need to be checked.

"Council began a process immediately after the incident at Black Head," Mr De Szell said.

"There is a visual inspection to see if there are any notable signs of decay.

"Also a number of chaps bigger than me shake the monuments to see how stable they are and some have since been placed on the ground."

Indy Lee Henderson was at the Black Head bowling club for her grandmother's birthday. ( Supplied:Facebook )

Mr De Szell said a plaque had been erected to honour Indy.

"We were always erecting a lookout but we did a plaque in her honour, liaising with her family," he said.

When extending her sympathies Deputy State Coroner Elizabeth Ryan noted that the plaque had brought Indy's family great comfort.

"She has gratitude for the council for the lookout as it is a very special place for her and has afforded her some peace."

Ms Ryan will hand down the inquest's findings on December 17.