Ms Batty was in the witness box for all of the second day of the inquest into Luke's death, and became distraught in the afternoon when she slammed the inability of police to arrest Mr Anderson before he killed their 11-year-old son at cricket training in Tyabb.

There were four warrants out for Mr Anderson's arrest and two intervention orders against him when he attacked Luke with a cricket bat and a knife on February 12, a week after Ms Batty provided police her former partner's address.

Mr Anderson, 54, was shot by police and died in hospital.

"The man was never important enough, he wasn't f...ing dangerous enough, he wasn't bad enough until now. Now he's done the worst," an emotional Ms Batty told the Coroners Court on Tuesday, after claiming it was "unfair" she be questioned at length for protecting her son.

Ms Batty said she would forever live with the anguish of letting Luke have a relationship with his father and believing he would never harm the boy.

"Can you imagine what that feels like? When someone wants to make you suffer for the rest of your life just to win. Even if it's sacrificing your own son. How can I ever understand that?

"I made the best decisions I could at the time. No one loved my son more than me. And I'm sitting here trying to make it better for him and I'll never get him back ... all I can do is (speak out) so some people out of all of you will learn."

Ms Batty said despite the history of violence Mr Anderson had displayed towards her, she could not get police to arrest him on intervention order breaches, lost count of how many times she was in court seeking orders, and became "sick" of counselling provided by the Department of Human Services.

"No one spoke to Greg. If he stopped being violent I wouldn't need counselling," she said.

Ms Batty said she "dealt with more police than I will ever know" in the 18 months before Luke's death, was "stressed out of my brain" and wanted more support than counselling from the DHS.

"I didn't want all the onus of responsibility to be on me. I wanted support and wanted other people to step in and make decisions to say 'no Greg', so I wouldn't have to incur his wrath," she said.

Mr Anderson faced an arrest warrant for child pornography charges when he attacked Luke, among others. The intervention orders against him comprised one preventing him from having any contact with Luke outside cricket and football matches at weekends and one taken out by a housemate a month before Luke was killed.

Ms Batty said she was "absolutely petrified" for Luke's safety when she learned of the child pornography charges, and decided then her former partner could not be alone with their son.

But the intervention order allowed him to chat with his son at sporting matches in the presence of others.

Ms Batty said she wanted Luke to have a relationship with his father and that she felt "torn" at being the one denying the man access to his son.

She told the court she had worried that Mr Anderson might have suicidal tendencies if left alone with his son, but never thought Luke would be in danger in a public place.

"I knew about Darcey Freeman, I knew about the Farquharson boys, but I didn't know their fathers and what their fathers were like with their (children)," she said.

"I didn't know Greg was capable of killing ... I thought while I was able to be around people that image of him (Mr Anderson) harming him (Luke) couldn't happen in a public place. That it couldn't happen at that bloody Tyabb oval and it did."

On the fatal day, Ms Batty could see Luke and his father practising in the cricket nets moments before the attack, with no one else around.

"It was a lapse of judgment on my behalf because everyone had gone home and clearly that was a situation I hadn't seen coming," she said.

State coroner Ian Gray will continue hearing Ms Batty's evidence on Wednesday.