The central conflict of the book emerges from the challenges Bo faces after her mother marries Bill and they become a part of a large, new family. This context is vital in the book, and the story explores the dynamics of blended families and sisterhood. Operation Sisterhood depicts both the advantages and the challenges of a blended family through Bo’s struggles to adjust to her new circumstances, demonstrating the importance of open communication in creating healthy family relationships.

The Dwyer-Saunders family is unusual in that they are not just a family by blood or marriage, but are co-housing families who live and raise their children together. Bo has to contend with a blend of fluidity and compromise in the way the family does things: There is openness and flexibility in how things are approached, especially education and learning. However, this flexibility is complemented with adjustments. One cannot always make independent and individualistic decisions, as Bo learns when she is thrown into the rotation for shared chores and swimming lessons, among other things.

Besides the particularities of the Dwyer-Saunders family setup, Bo also has to contend with the general changes of moving from a single-child and single-parent home to a larger, blended family.