She also added the older accused was half asleep when he was asked to take part.
"He didn't seem keen, he didn't want to."
It's been revealed the house the boys were staying at was well-known as a place to buy synthetic cannabis. The witness told the jury those staying at the house had been using the drug the night before the incident.
Earlier the witness, who is giving evidence via closed-circuit television in another part of the court, described the schoolboys as being in "shock" when they returned to the house, saying the older accused was covered in blood and she thought he must have cut his arm by breaking a window while robbing the shoe store. She didn't believe him when he told her he thought he killed someone, saying it was because the shopkeeper had tried to hit the younger boy.
Under cross examination by defence lawyer Maria Pecotic, she said the accused told her he didn't mean to kill anyone, and that he'd only meant to scare.
Lawyers for the two boys, who have name suppression, argue they lacked the "knowledge and intent" to commit the crimes.
The family of Mr Kumar is in court again today on the first anniversary of his death.
"It's a hard day but they wanted to be in court for this witness to hear what she has to say, as she was the other one in the house that day," Crown lawyer Kieran Raftery said.
The Crown is expected to wrap its case on Friday, with the defence opening on Monday.