A 12-year-old boy who stole from a pizza delivery driver and caused $6,000 damage to a vehicle at a construction site was being supplied with cannabis by his family at the time, a court has heard.

Karratha's Children's Court was told the boy's siblings, family and peers had been providing him with cannabis when he committed two offences earlier this year, including damaging the vehicle and stealing from a Domino's delivery driver.

In the second incident, the court heard the driver had stopped in a street in the Karratha suburb of Nickol when the boy and an alleged co-accused approached and stole his wallet, which had $200 in it.

The boy was arrested days later and admitted to police the theft of the delivery driver was his idea.

At the time of the offences, the boy was already on a separate community-based order requiring he liaise with Youth Justice and attend programs — which he had — for his previous offending.

The court heard in November the boy and an alleged co-accused approached a Chinese national, 24, in the Karratha Library and snatched the woman's backpack, which contained her passport and more than $1,000.

He was charged with common assault for that incident and when later found by police, told officers the money had been "given away" to others.

Earlier that month the boy stole two cartons of cigarettes from a store in Karratha after waiting for a staff member to be distracted.

Karratha Magistrates Court heard the 12-year-old boy was being supplied with cannabis by family members and friends. ( ABC Pilbara: Susan Standen )

Boy 'too young' for community service: magistrate

In her sentencing remarks, Magistrate Michelle Ridley commented the boy's record was "significant for his age" and said if he was older she would have considered harsher penalties, but said he was "too young" for community service.

She said a report provided to the court set out there were "a lot of difficulties" in his family, which were not his fault, but she said that had certainly accounted for some of the boy's offending.

"The concerning factor is you admit you're still using cannabis … and your siblings, your family and peers they provide it to you and that is very wrong," Magistrate Ridley said.

"[The report notes] they do not think the cannabis is contributing to your offending."

The boy's lawyer, George Giudice, said he had been in contact with the boy's brother who had been "quite hard" on him recently and said that impact seemed to have seen the accused turn a corner.

"Last week his brother said he had been abiding by all the instructions … playing games and even helping around the house," Mr Giudice said.

"They said he even went to school and was doing the right thing … I spoke to Youth Justice who said he seemed to be doing quite well."

Mr Giudice asked the magistrate to give the boy a "chance to keep up his good work".

The 12-year-old was placed on a new six-month community-based order, which Magistrate Ridley commented was a long time for someone his age, but needed to be significant enough to ensure sufficient punishment.

That order means the boy will have to report to Youth Justice staff and attend offender programs.