I think that's the main reason behind the low participation of women in C++, many women simply don't find C++, and/or programming in general, very interesting as an occupation (similarly to matchbox toy cars). I've not seen that personally. More than half the class in a teenage coding school is usually female. 40% of those taking a Masters in eCommerce which I used to tutor were female. Back when I used to be involved with startup incubators, it was usual for a quarter to a third of the programmers to be female, but do note it was mostly in Javascript and web programming.
I think women find programming interesting as an occupation just as much as men. Just probably not in C++, except for a small subset. Some of the female Physicists and Mathematicians I've known well found C++ very interesting, and very tempting, given the pay differential over academia. None I knew made the jump, though, there are big advantages to being female in academia. Niall