As per § 401.75 of the Social Security Administration,
https://www.ssa.gov/OP_Home/cfr20/401/401-0075.htm
A parent or legal guardian of any minor or an individual who has been declared incompetent can act on behalf of the minor or incompetent individual. This means that they will have the same rights and privileges as the individual they represent, except for certain circumstances outlined in other sections of the regulations. Specifically, there are procedures in place to verify an individual’s identity and special procedures for notification of or access to a minor’s medical records. As a result, the authorized representative will be treated as if they were the individual they represent in most situations.