Mr Wilson said the boy turned to his mother and said, "Mum, she just hit me," before standing between his mother and grandmother for protection. Rimene continued to abuse the frightened young boy and walked over to him, grabbed him and shoved him against the wall of the bank.
She then allegedly punched him a second time, on the arm. As a result of the punches, the boy received a reddened upper arm.
Mr Wilson said Rimene continued her verbal tirade towards the boy and said: "I am going to kill you, I know what you look like."
The boy's mother grabbed him, moved him to safety and told Rimene: "He is only 7 years old."
Rimene shouted more threats and then walked away along Queen St towards Church St as police were called, Mr Wilson said.
Soon afterwards, Rimene was located on Church St and arrested. As she was being put into the patrol car, she turned to the boy's mother who was nearby and allegedly said: "I know your son's face and I'm going to slit his throat when I see him again."
Police said Rimene admitted everything and that she "hated white children", and repeated her threat to kill the boy if she ever saw him again. She had not previously appeared before the court.
Mr Wilson told Judge Broadmore both the boy and his family were "extremely shaken up" by the incident.
He said the victim's family had never seen Rimene before but were worried she could carry out her threats.
Judge Broadmore said he wanted a mental health assessment prepared on Rimene, which would verify if her mental health was under strain when the incident occurred.
She was remanded on bail until June 27, without plea.