Childless Family/Couple. Couples without children, and they choose to not have them. They feel they are not ready or responsible for another's life. Some are not physically able to have children. They have more freedom for career choice. An example of this would be in Grey's Anatomy: Owen and Christina.
Single-Parent Families. Have a mother and a follow at the head of a household. Both parents either have full custody or partial. One parent has the total caregiver role and have roles within the household. An example of this would be Toy Story.