Adults need to fill out their own waiver. For those under 18, a waiver must be completed by a parent or guardian.
Your waiver expires at the end of the calendar year, or when you turn 18. Simply do a new one!
When you do the waiver, just choose Adults and Minors and pick 3 minors. Then provide the name and date of birth of each, and your emergency contact info, and all 4 will be completed with one form and one signature.