When setting up your event there's an "Additional Option" to "Check in by Family." Many people mistakenly assume that this means that the entire family will be automatically checked in with a single click. While this is not true, for accurate reporting. When you select the option to "Check In by Family", the Check In Screen simply pulls up the Family list so you can check in the members of the family that should be checked in.
Example of Check In Screen
This is what you should expect to see on your check-in screen as you check in one family member in a family.
Note: You will only receive one parent tag for all the children you've checked in, not a parent tag per child.