Harvey’s killer was found guilty of his murder on Friday at Sheffield Crown Court.
The trial judge, Mrs Justice Ellenbogen, is expected to make a decision on whether to lift the order when the 15-year-old is sentenced in October.
Harvey’s parents, who have set up a youth club in his memory, reiterated their earlier call to install knife arches in schools.
“Get knife arches in, then get educating children about the pure devastation that knife crime brings,” said Mrs Willgoose.
“Children know there are knives in schools. Something needs to be done.”
Mrs Willgoose, who has campaigned against knife crime since her son’s death, added: “If you don’t think there’s a problem, ask your child if they have ever known of anybody bringing a knife into school.
“I think parents would be very interested in their answer.”
Mrs Willgoose said her son avoided school in part due to anxiety caused by the coronavirus pandemic, but also because of a fear about knives in schools.
Harvey’s dad Mark said the youth club, Harvey’s Hub, would teach young people about the dangers of knife crime.
He said the family had previously met with Home Secretary Yvette Cooper to discuss the issue.