Must an employer permit a 16 or 17 year old to be accompanied by a parent at a disciplinary or grievance hearing?

No. A worker does not have a statutory right to be accompanied by a family member at a disciplinary or grievance hearing, unless the family member is a work colleague or trade union official, in which case he or she will be a permissible companion under the statutory right to be accompanied. Having said that, there is nothing to prevent an employer from allowing a worker to be accompanied by a family member and it may be appropriate to allow this in the case of a very young individual.