Final answer:
Sheila's choice to have children later while continuing her career is an example that challenges the normative timing of life events, demonstrating a move away from traditional family life cycle stages and embracing a more fluid understanding of family development.
Step-by-step explanation:
The decision by Sheila to continue working and have children later in life questions the normative timing of life events. She exemplifies a deviation from the early stage theories of the family life cycle, which tended to prescribe a set sequence of life stages including early childbearing and dedicated homemaking.
Models like the family life course recognize the fluidity of family development and acknowledge that childbearing may not always coincide with marriage. Today's society is steering away from rigid structures and embraces variations in family practices, acknowledging the evolving roles of women and the economic realities that sometimes push child-rearing to a later time. Sheila's story aligns with changing social norms and underscores the need for adaptability in our understanding of family development and the life cycle.