Unfortunately it is everything. I was wrong about the age though, its under 13, not 18.
Family & Friends in My Disney Experience – Frequently Asked Questions
Q:
In My Disney Experience, how can multiple adults or teens make plans for a child?
A:
In the
Family & Friends section of
My Disney Experience, you can create a profile for a child under age 13 simply by entering the name and age.
The person who creates a child’s profile will manage the profile and all the plans for that child. The child’s profile cannot be transferred to another person to manage.
Only create one profile per child. Creating multiple profiles for an individual may result in issues accessing travel plans and
Lightning Lane entrances.
Any Guest age 13 and older who does not have a Disney account may create an account at any time. If you make plans on behalf of a Guest who later creates a Disney account, be sure to invite that Guest to connect with you in Family & Friends using his or her Disney account email. This allows the plans you’ve made to migrate to the other Guest’s account.