relative of a dependent adult. A trustee is someone who handles the financial and legal affairs of a dependent adult.
Depending on your teen's disability, you may want to consider trusteeship or guardianship in your transition plan.
Once your teen is 18, and if you are not your teen's guardian or trustee, Disability Service Office staff and other staff at the education institution will not be able to communicate with you about your teen's progress without your teen's written permission.