Fractions remains a difficult topic for primary preservice teachers (PST). This paper analyses a PST teaching episode using the "Refined Consensus Model" (RCM) of Pedagogical Content Knowledge (PCK) to explore challenges faced by PST in acquiring specialised knowledge for effective fractions teaching. Data include semi-structured interviews highlighting relationships between collective and personal PCK with a videotaped teaching episode allowing an interrogation of her enacted PCK. Key findings illustrate the relationships among a PST collective, personal, and enacted PCK, and the importance of the reflection phase of enacted PCK.