Event Registration Check In Should Only Feature Registered Children

One thing we noticed during our VBS last week, was that children who weren't registered for VBS were still able to be checked in under their parent's account. Our attendance numbers didn't match the number of kids registered, which was frustrating. When parents go to check in their child(ren) during an event, there should be an option to register their child from the check in screen, but most importantly, children shouldn't be checked in if they aren't registered for the event.