This paper explains the methods used in a grounded theory analysis of the experience of 55 first-time mothers in Australia, presented in the first of this series of two papers. The categories identified in the research are realising, readiness, drained, aloneness, loss and working it out, encompassed in the core category becoming a mother. Specifically, this paper extends the analysis and explains the application of a 'paradigm model' and the identification of a Basic Social Process (BSP). The paper links the analysis to the literature on early motherhood from nursing, midwifery, feminist, and sociological research. A substantive theory is proposed to explain women's experience in becoming mothers that demonstrates how, when responsive to the needs of those researched, a grounded theory analysis can provide a framework for nursing and midwifery care.