I also wonder to what extent the characteristic “interested in working with children” comprises others like “expected to be working with children” and “familiar with working with children”, and so on.
People’s career choices tend to be heavily influenced by their socialization, and society encourages girls and women into caring-for-children roles pretty much from the get-go: older sisters get more expectations of caring for younger siblings than older brothers do, girls are steered towards babysitting jobs more than boys are, and so on. At even younger ages, girls are much more encouraged to engage in “pretend childcare”, in the form of playing with dolls, than boys are. And so on.