Using the Parent Portal, you can see and update information for children you have been linked to by your school.
If you have other children at the same school but can't see them, it may be that they haven't been linked to your account.
You'll need to contact your school to get them to link you together. If you have been linked to the right students, they will need to make sure there are no accounts with duplicate emails.
You'll only be able to see children who have attended that school within the current academic year. If you have other children at another school who use Arbor, you'll need to log in to the other school's site to see your other child.