When we give parents the portal link, it's going to charge them to just add their details in the system. This can cause friction, and some might start filling in their details but not submit the form. (We then don't have leads.) I think the registration form needs to be done separately from choosing classes; therefore: Step 1: add details and have the ability to add more than one child. Step 2: register for classes, which then includes the payment. The payment should only be once, not per class. Side note: It would make a great automation, "Hey, we noticed you registered {child name} but didn't select any classes. Can I help you with that?"