Final answer:
Lilian Katz's quote reflects the viewpoint that in the context of child development, professionals should consider the entire family as their client, not just the individual child, because the family is a social construct that significantly influences child development.
Step-by-step explanation:
Lilian Katz's quote, “Your client is not the child, but the family,” emphasizes the importance of viewing the child within the context of their family unit, rather than in isolation. The quote is in agreement with the social construct theory which posits that families are not purely objective entities but are rather defined by ongoing social interactions and evolving social norms. This understanding of family also resonates with the perspectives of interactionists who argue that the definition of family is flexible, encompassing traditional structures as well as any union characterized by respect and compassion. Lillian Katz's perspective aligns with that of other experts in the field, indicating the significance of the family's influence on a child's development, as suggested by Minuchin's research on families and individual development.