The aims of this paper are twofold. The first aim is to show the complexity of the determinants leading to gender identity formation via the longitudinal study of one female research subject over 33 years. Focus is on the origins, meanings and functions of masculine character traits accrued at each phase of development. The second aim is to show that character formation begins early in the second year of life and that early patterns have a certain continuity with adult character despite reorganizations of the oedipal phase and subsequent contributions from each phase of development. Discussion focuses on the complicated nature of female gender identity formation.