Interesting looking paper "Mathematics—a Critical Filter for STEM-Related Career Choices? A Longitudinal Examination among Australian and U.S. Adolescents." - article on it here:
The perceptions of parents in Australia had a significant impact on their children's future, and many youngsters took careful note of these before making career choices. Mothers tended to hold their sons' mathematical ability in higher regard. Their thoughts about their daughters' maths ability were much more tied to actual maths achievements, such as test scores. These findings point to a gender bias in mothers' judgments about sons versus daughters, or might reflect differences in the self-concept that male and female adolescents hold of themselves. These therefore highlight the impact that parents can have in encouraging or discouraging their children's STEM career aspirations.