New families are automatically created when you add a new person to the system. The person will be the head of household of their own family. Their initial position is selected from the "New Person" pop up under the "General > Family" section.
People can be part of multiple families, but can only have one marked as primary at any given time. The primary family is what appears in reporting and within the check-in system.
Creating New Families
You will need the Limited Write People permission to perform this action.
There are times you will want to create a new family from an existing one. Reasons include a child getting married, turning 18, and many others. To do this, navigate to that person's profile and click on the "Family" tab. Next, open the drop down next to the person you would like to add to a new family, and select "Create new family." You can also do this from any other member of that person's family (as shown below).
The person will remain in their previous family, but will also be added as an adult to a new family as well as marked the head of household. This new family will become their primary family.