Got a story? Text: 63000 - Email: talkback@the-sun.co.ukSara Corran was attacked with a roasting knife during an argument with the boy's mother - Ms Corran's neightbour - in their Liverpool home on Thursday evening.
The boy is understood to have grabbed a kitchen knife and stabbed Ms Corran in the buttock, leg and arm.
He was interviewed by Merseyside Police but not arrested as he is below the age of criminal responsibility.
He returned home today and was later driven away without his mother. He left the terraced house with a coat over his head to avoid photographers.
Earlier, he and his mother told ITV Granada Reports they were sorry for what had happened.
He said: "“I ran into the kitchen where the roasting knives was, and I got a knife and I stabbed her in the bum."
Asked if he would do it again, the boy replied: "No. I would phone the police and say theres been a fight."
His mother, who was visibly upset, said: "He must have a lot of anger in him.
"I know he probably didnt know what he was doing at the time, because he was frightened, but I dont know what made him think of the knife."
Ms Corran was taken to hospital by ambulance, where she remained today. Her injuries were described by police as “serious but not life-threatening”.
The two women, both single mothers, live in the Norris Green area.
Neighbour Maureen McGee said she believed the lad acted to protect his mother.
She said the boy “is a mischievous little boy, like all young lads".
The woman added: “He plays outside a lot and hes had my flowers up before, but hes not a bad lad or a wild child.
“Hes a nice little lad but I think last night hes seen the red mist and tried to protect his mum.
“Its absolutely terrible.”
Another neighbour said the mothers "are good friends but they argue and fight a fair bit when they have a drink together".
A spokeswoman for Merseyside Police said: "“The investigation is ongoing, and we will be working with other appropriate agencies."
A spokesman for Social Services said they were working with partner agencies regarding the incident.