Although substantial gender differences in motivation, engagement and enrolment behaviour are frequently reported in the international physics education literature, the majority of studies focus on students who intend to choose physics for their future study. The present multi-occasional study examines the gender difference in motivation, engagement and enrolment behaviour among senior secondary students from New South Wales schools who have already chosen to study physics. It examines whether the differences reflect differences of "degree" in these dimensions, or differences of kind for these students. Fine-grained analyses at module-specific level of the senior secondary physics curriculum indicated that the differences do not represent differences of "kind." That is, girls' and boys' perceptions of the key facets of motivation, sustained engagement and choice intentions in relation to physics seemed to be qualitatively the same. However, there were differences in the degree to which boys and girls are motivated, although the pattern was inconsistent across the four modules of the senior secondary physics curriculum. Girls' motivation, engagement and sustained enrolment plans in relation to physics were found equal to or higher than boys' at various time points through the course. These findings highlight the need to change the existing gender-biased stereotype that students perceive physics as a male domain and that subjective motivation, engagement and enrolment plans will always report higher measures for males. The results have implications for intervention strategies aimed at sustaining student motivation in physics. The potential implications of the findings for practitioners and researchers are discussed.