Research has shown that girls' confidence and ability perception are critical to their beliefs, attitudes, and interests concerning the pursuit of mathematics and science. In historically male-dominated fields, females often have a tenuous relationship with STEM (Science, Technology, Engineering, Mathematics) disciplines. This autoethnographic study explores one girl's trajectory away from a keen interest in mathematics and science in favour of social sciences. Four central themes were identified as critical to females' interest, pursuit, and advancement into STEM careers, including gender-based socialisation; confidence, ability, and achievement; classroom environment and school curriculum; and family 'curriculum making'. The findings that impacted the divergence from STEM are revealed through interviews with the author's parents and expressed through a reflexive narrative. The findings in this paper suggest several actions that families and schools might take to support the STEM aspirations of young female students.