How might this responsibility affect their normal course of adult development?

Grandparenting can be highly rewarding. Many grandparents, though, unexpectedly become guardians and raise small children. How might this responsibility affect their normal course of adult development? What components might require transitions? How would a professional counselor encourage these older guardians in their new roles?
This discussion question meets the following CACREP Standard: 2.F.3.f. Systemic and environmental factors that affect human development, functioning, and behavior.