Yes. You can ask anyone you wish to help you, as your representative, with any dealings you have with your boss or supervisor. This person can be your parent or guardian, a family friend, or anyone else that you know and trust. You can also have a professional person like a union rep or a lawyer represent you.
Your representative can be a support person, but can also speak on your behalf if you are not confident in dealing with your boss yourself. Having a representative may be especially useful when you are negotiating your new terms and conditions of employment, or you are dealing with a problem or issue at work. Your representative can help you understand your employment agreement and the implications of any discussions you have with your boss.