The Parental Subsystem- When the first child is born, the family has parental subsystem which composed of mother and father.- Parents have their roles on parenting and they have to make room for an additional relationship – that is, with the child.- It is mainly child-focused.3. The Sibling Subsystem- In this subgroup, children learn how to relate to one another, such as how to share, disagree, make friends, bargain and protect themselves.- This will have an important influence on the child’s growth and development.