This paper refocuses attention on and problematizes girls' experiences of school achievement and the construction of schoolgirl femininities. In particular, it centres on the relatively neglected experiences and identity work of high achieving primary school girls. Drawing upon ethnographic data (observations, interviews, and pupil diaries) from a broader study of girls' and boys' perceptions and experiences of schoolwork and achievement from two contrasting primary schools in a city in South Wales (UK), the paper will explore the gendered subjectivities of high achieving girls from diverse social and cultural backgrounds. Three narrative case studies are re-presented and analysed to explore the feminization of success and thus the tensions and contradictions as girls negotiate the pushes and pulls to be both "bright" (i.e. succeeding academically) and "beautiful" (succeeding in "doing girl"). Of key interest are the possibilities, costs, and consequences of girls producing ambivalent femininities and the rearticulation and transgression of normative ways of "doing clever" and "doing girl" in 21st century primary schools. (Contains 6 notes.)