Book excerpt: Psychological theory has traditionally overlooked or minimized the role of siblings in development, focusing instead on parent-child attachment relationships. The importance of sisters has been even more marginalized. Sue A. Kuba explores this omission in The Role of Sisters in Women's Development, seeking to broaden and enrich current understanding of the psychology of women. This unique work is distinguished by Kuba's phenomenological method of research, rooted in a single prompt: "Tell me about your relationship with your sister." Rich in detail, the responses (many of which are reproduced at length within the book) provide a complex picture of sister relationships across the lifespan. Integrating these stories with current literature about gender and family composition for sisters of difference (disabled and lesbian sisters) and ethnic sisters, this book provides useful recommendations for therapeutic understanding of the significance of sisters in everyday life, integrating diverse perspectives in order to address the ways clinicians can enhance psychological work with women clients. A valuable contribution to the field of mental health, The Role of Sisters in Women's Development is highly recommended for therapists who wish to broaden their inquiry into the sister connection, as well as anyone who wants to further understand the importance of sisterhood.