We recommend each nuclear family creates its own family account. So whether you're a typical family with parents and kids or a couple or even a group house shared by your best friends, create one family account and add all the "household" family members to it.
After you've created your family account invite other families to join your Tribe. Your Tribe is the group of families your family is connected to.
Stretch's design, color system, search system, and security system works far better when each family has its own account. However, there is no limit to the number of family members. So if you're wanting to use Stretch for your football team (and lots of people do) it's fine with us.