She said Bradyn's father Graham Dillon was always a step ahead of her and seemed to know how to play the system.

"Graham was a master manipulator," she told the ACT Coroner's Court.

Dillon, 41, is serving more than three decades in jail for murdering the nine-year-old boy, a murder that came after months of vicious beatings.

The inquest is examining how Bradyn became so vulnerable and isolated before his death.

It will also consider the response of various authorities including ACT health, education, child protection and police.

The inquest has heard how Dillon took out a protection order against Bradyn's mother and manipulated those around him to keep the boy in Canberra.

Bradyn's stepmother, Dillon's new partner, said he would tell the boy his mother was on drugs and that "mummy's not the same mummy, mate".

Bradyn's mother, whose name is suppressed, said Dillon made it known that they were not allowed to talk about their home life.

"If you talk you get beaten."

The boy's mother was questioned by a barrister representing ACT health, education and child protection services.

She agreed that Dillon was always a step ahead of her in keeping Bradyn in Canberra. And that she felt extremely overwhelmed by the number of services with who she had contact.

"I didn't know which direction to take, there's no guidelines. I was stuck. I didn't know where to turn."

Asked if there was something she wished had been there, she said: "Just somebody to listen to me from the beginning."

She said: "With a lot of people in my position we don't know the law courts.

"You don't ever know what you can do but when you get in that situation you're helpless."

Also on Wednesday, Bradyn's stepmother, who married Dillon after Bradyn's mother and he had separated, detailed Dillon's horrific emotional and physical abuse.

The woman described, for example, how Dillon had once used a wire coat hanger to strangle her.

In another, he smashed her guitar over her head and legs.

Bradyn had come to live with his stepmother and Dillon to help the boy's mother in 2013.

Eventually the stepmother left Dillon and was granted a domestic violence order protecting herself and her children.

She said Dillon repeatedly made contact with her, she believed in breach of the order.

But she said police told her they could not act, because they could not be sure it was Dillon who wrote the Facebook messages.

Bradyn's mother was trying to take back care of the boy but Dillon was resisting.

Despite her efforts he was murdered before being returned to his mother.

The inquest continues.