Answer
The juvenile will be placed in a secure room (or cell if no secure accommodation is available). The police will try to identify the person responsible for the welfare of the juvenile as soon as possible and inform that person that the juvenile has been arrested, why the juvenile has been detained and where they are being detained.
The parent/guardian will be asked to attend the police station as soon as possible to see the juvenile. The juvenile will be given his/her rights in front of the parents even if they have been previously given. The parent/guardian can request to speak to the juvenile in private, this is however, discretionary.
Under 16s must be given access to a solicitor prior to the interview and should not be allowed to waive this right (regardless of the parents' viewpoint).
In the interests of fairness however, in most cases the request is likely to be granted. The parent/guardian will be present (along with a solicitor if requested) during the interview and at the rest of the procedure at the police station.
However, if you are a witness or involved in the case or any admissions were made to you then you will not be allowed to be involved.