How can both the family structural theory and the family developmental theory be applied to this scenario?

Mrs. Jones, a widow, is no longer able to live independently and is requiring more and more help with her self-care. Her daughter, Susie, who is married with three school-aged children, agrees to let her mother move in with her. Susie is concerned with balancing the demands of her career and the needs of her family, especially now that her elderly and chronically ill mother will need assistance. She is also unsure about how she feels with the reversal of roles, having to now be the primary caregiver of her mother. How can the nurse, caring for this family, assist with the changes they are about to undergo? How can both the family structural theory and the family developmental theory be applied to this scenario? How can health education enhance health promotion for this family?