Who used family members for labor?

Answer 1

Until the industrial revolution, it was common (even usual) for family members to participate in the "business" of the head of the family. This included children and sometimes wives, and was true for smiths, barbers, farmers, rulers, and most other fields of endeavor. With the industrial revolution, over time the practice became less common but never died out.

Children still do work on their parents' farm, even operating farm machinery. It is less common for family members, especially young ones, to labor in family commercial fishing or medical practice.